Difference between revisions of "Chondro-osseous tumours"

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'''Chondro-osseous tumours''' occasionally cross the desk of the pathologist.  They are grouped together as [[bone]] may develop from [[cartilage]].
[[Image:Osteosarcoma - very high mag.jpg|thumb|250px|right|A chondro-osseous tumour ([[osteosarcoma]]). [[H&E stain]].]]
'''Chondro-osseous tumours''' occasionally cross the desk of the pathologist.  They are grouped together as [[bone]] may develop from [[cartilage]].  


Primary bone tumours are rare; the most common bone tumour is [[metastases]].<ref name=Ref_WMSP632>{{Ref WMSP|632}}</ref>   
Primary bone tumours are rare; the most common bone tumour is [[metastases]].<ref name=Ref_WMSP632>{{Ref WMSP|632}}</ref>   
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===Common malignant===
===Common malignant===
*Osteosarcoma.
*[[Osteosarcoma]].
*Chondrosarcoma.
*[[Chondrosarcoma]].
*Ewing's sarcoma.
*[[Ewing's sarcoma]].
*Multiple myeloma.
*[[Multiple myeloma]].
*Metastases.
*[[Metastases]].
**Most common tumours metastatic to bone (mnemonic: ''BLT with Ketchup & Pickles''):  
**Most common tumours metastatic to bone (mnemonic: ''BLT with Ketchup & Pickles''):  
***[[Breast]].  
***[[Breast]].  
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***[[Prostate gland]].  
***[[Prostate gland]].  


Epidemiology:<ref>TN05 OR42.</ref>
Epidemiology:<ref name=Ref_TN2005_OR42>{{Ref TN2005 |OR42}}</ref>
*Osteosarcoma -> 2nd decade.  
*Osteosarcoma -> 2nd decade.  
*Ewing's ->5-20 yrs.
*Ewing's ->5-20 yrs.
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===Malignant bone tumours by age===
===Malignant bone tumours by age===
Most common by age:<ref>TN05 OR42.</ref>
Most common by age:<ref name=Ref_TN2005_OR42>{{Ref TN2005 |OR42}}</ref>
*<1 year old - [[neuroblastoma]].
*<1 year old - [[neuroblastoma]].
*1-10 years old - [[Ewing sarcoma|Ewing's]] of tubular bones.
*1-10 years old - [[Ewing sarcoma|Ewing's]] of tubular bones.
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===Benign aggressive bone tumours===
===Benign aggressive bone tumours===
*Giant cell tumours.
*[[Giant cell tumour of bone]].
*Osteoblastoma.
*[[Osteoblastoma]].
**Thought to be related to osteoid osteoma.
**Thought to be related to [[osteoid osteoma]].
**If in long bones often diaphyseal.
**If in long bones often diaphyseal.
Ref.:<ref>TN05 OR41.</ref><ref>URL: [http://www.emedicine.com/RADIO/topic494.htm http://www.emedicine.com/RADIO/topic494.htm].</ref>
 
Ref.:<ref name=Ref_TN2005_OR41>{{Ref TN2005 |OR41}}</ref><ref>URL: [http://www.emedicine.com/RADIO/topic494.htm http://www.emedicine.com/RADIO/topic494.htm].</ref>
   
   
===Summary tables===
===Summary tables===
====Bone tumours====
====Bone tumours====
{| class="wikitable sortable" style="margin-left:auto;margin-right:auto"
{| class="wikitable sortable" style="margin-left:auto;margin-right:auto"
| Entity
! Entity
| Key feature
! Key feature
| Other features
! Other features
| Radiology / gross
! Radiology / gross
| Clinical
! Clinical
| Stains / other
! Stains / other
| Image
! Image
|-
|-
| [[Osteoma]]
| [[Osteoma]]
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| ?
| ?
| no stains / may be assoc. with [[FAP]]
| no stains / may be assoc. with [[FAP]]
| Image (???)
| [[Image:Osteoma -- intermed mag.jpg |thumb|center|150px| Osteoma. (WC)]]
|-
|-
| [[Osteoid osteoma]]
| [[Osteoid osteoma]]
| osteoblastic rimming
| osteoblastic rimming
| anastomosing bony trabeculae
| anastomosing bony trabeculae
| <= 1.5 cm
| must be <2 cm,<ref name=pmid25224389>{{Cite journal  | last1 = Yalcinkaya | first1 = U. | last2 = Doganavsargil | first2 = B. | last3 = Sezak | first3 = M. | last4 = Kececi | first4 = B. | last5 = Argin | first5 = M. | last6 = Basdemir | first6 = G. | last7 = Oztop | first7 = F. | title = Clinical and morphological characteristics of osteoid osteoma and osteoblastoma: a retrospective single-center analysis of 204 patients. | journal = Ann Diagn Pathol | volume = 18 | issue = 6 | pages = 319-25 | month = Dec | year = 2014 | doi = 10.1016/j.anndiagpath.2014.08.006 | PMID = 25224389 }}</ref> metaphysis
| painful, NSAIDs remove pain, young
| painful, NSAIDs remove pain, young
| IHC / other
| IHC / other
| [http://commons.wikimedia.org/w/index.php?title=File:Osteoid_osteoma_-_low_mag.jpg low mag.], [http://commons.wikimedia.org/w/index.php?title=File:Osteoid_osteoma_-_high_mag.jpg high mag.]
| [[Image:Osteoid_osteoma_-_high_mag.jpg |thumb|center|150px| Osteoid osteoma. (WC)]]
|-
|-
| [[Osteoblastoma]]
| [[Osteoblastoma]]
| osteoblastic rimming
| osteoblastic rimming
| anastomosing bony trabeculae
| anastomosing bony trabeculae
| > 1.5 cm
| must be >1 cm,<ref name=pmid25224389/> often >=2 cm, metaphysis
| not painful
| not painful
| IHC / other
| IHC / other
| [http://commons.wikimedia.org/wiki/File:Osteoblastoma_-_low_mag.jpg low mag.], [http://commons.wikimedia.org/wiki/File:Osteoblastoma_-_high_mag.jpg high mag.]
| [[Image:Osteoblastoma_-_high_mag.jpg|thumb|center|150px|Osteoblastoma. (WC)]]
|-
|-
| [[Ewing sarcoma]]
| [[Ewing sarcoma]]
| [[small round blue cell tumour]]
| [[small round blue cell tumour]]
| cytoplasmic clearing (due to glycogen)
| cytoplasmic clearing (due to glycogen)
| Radiology / gross
| usu. diaphysis
| pediatric
| pediatric, typically 1-10 years
| PAS+, PASD-  
| PAS+, PASD-, [[chromosomal translocations]] (usually t(11;22)(q24;q12)) 
| [http://commons.wikimedia.org/wiki/File:Ewing_sarcoma_-_intermed_mag.jpg intermed. mag.], [http://commons.wikimedia.org/wiki/File:Ewing_sarcoma_-_PAS_-_high_mag.jpg high mag. - PAS]
| [[Image:Ewing_sarcoma_-_PAS_-_high_mag.jpg |thumb|center|150px| Ewing sarcoma. [[PAS stain]]. (WC)]]
|-
|-
| [[Osteosarcoma]]
| [[Osteosarcoma]]
| osteoid
| osteoid
| Other features
| +/-hemorrhage, +/-cartilage
| Radiology / gross
| distal femur, prox. tibia, prox. humerous
| Clinical
| typically 10-30 years, pain, swelling
| no stains; many subtypes
| no stains; many subtypes
| [http://commons.wikimedia.org/wiki/File:Osteosarcoma_-_very_high_mag.jpg very high mag.]
| [[Image:Osteosarcoma_-_very_high_mag.jpg |thumb|center|150px|Osteosarcoma. (WC)]]
|-
|-
| [[Giant cell tumour of bone]]
| [[Giant cell tumour of bone]]
| abundant giant cells
| abundant giant cells
| nuclei of surrounding cells similar to those in giant cells
| nuclei of surrounding cells similar to those in giant cells
| Radiology / gross
| growth plate of long bones
| Clinical
| 20-45 years old, +/-joint pain, +/-immobility
| IHC / other
| IHC / other
| [http://commons.wikimedia.org/wiki/File:Giant_cell_tumour_of_bone_-_high_mag.jpg high mag.]
| [[Image:Giant_cell_tumour_of_bone_-_high_mag.jpg|thumb|center|150px|Giant cell tumour. (WC)]]
|-
|-
|}
|}
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====Cartilage tumours====
====Cartilage tumours====
{| class="wikitable sortable" style="margin-left:auto;margin-right:auto"
{| class="wikitable sortable" style="margin-left:auto;margin-right:auto"
| Entity
! Entity
| Key feature
! Key feature
| Other features
! Other features
| Radiology / gross
! Radiology / gross
| Clinical
! Clinical
| Stains / other
! Stains / other
| Image
! Image
|-
|-
| [[Chondroma]]
| [[Chondroma]]
| ctyologically benign cells
| ctyologically benign cells
| equally spaced nests
| equally spaced nests
| Radiology / gross
| usu. diaphysis
| benign / DDx: chondroma, well-diff. chondrosarcoma
| benign / DDx: chondroma, well-diff. chondrosarcoma
| IHC / bone marrow cavity chondroma = ''enchondroma''
| IHC / bone marrow cavity chondroma = ''enchondroma''
| [http://commons.wikimedia.org/wiki/File:Enchondroma_-_very_high_mag.jpg very high mag.]
| [[Image:Enchondroma_-_very_high_mag.jpg |thumb|center|150px| Enchondroma. (WC)]]
|-
|-
| [[Chondroblastoma]]
| [[Chondroblastoma]]
| abundant extracellular material, abundant eosinophilic cytoplasm
| abundant extracellular material, abundant eosinophilic cytoplasm
| calcifications surround cells nests ("chickenwire" appearance) - '''classic'''
| calcifications surround cells nests ("chickenwire" appearance) - '''classic'''
| Radiology / gross
| epiphysis
| DDx: [[giant cell tumour of bone]]  
| DDx: [[giant cell tumour of bone]]  
| S100+ve, vimentin +ve
| S100+ve, vimentin +ve
| [http://commons.wikimedia.org/wiki/File:Chondroblastoma_-_very_high_mag.jpg very high mag.]
| [[Image:Chondroblastoma_-_very_high_mag.jpg |thumb|center|150px| Chondroblastoma. (WC)]]
|-
|-
| [[Chondrosarcoma]]
| [[Chondrosarcoma]]
| cartilaginous appearance +/- nuclear atypia
| cartilaginous appearance +/- nuclear atypia
| Other features
| lack osteoid, if present -> osteosarcoma
| Radiology / gross
| usu. diaphysis, classically hip; almost never distal extremity
| Clinical
| >40 years old
| IHC / may be histologically benign looking
| IHC / may be histologically benign looking
| [http://commons.wikimedia.org/wiki/File:Chondrosarcoma_%282%29.jpg high mag.]
| [[Image:Chondrosarcoma_%282%29.jpg |thumb|center|150px|Chondrosarcoma. (WC)]]
|-
|-
|}
|}
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====Other====
====Other====
{| class="wikitable sortable" style="margin-left:auto;margin-right:auto"
{| class="wikitable sortable" style="margin-left:auto;margin-right:auto"
| Entity
! Entity
| Key feature
! Key feature
| Other features
! Other features
| Radiology / gross
! Radiology / gross
| Clinical
! Clinical
| Stains / other
! Stains / other
| Image
! Image
|-
|-
| [[Osteochondroma]]
| [[Osteochondroma]]
| Key feature
| benign bone and cartilage
| Other features
| Other features
| Radiology / gross
| metaphyseal lesions
| Clinical
| Clinical
| IHC / other
| IHC / other
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| bisphasic - stroma & epithelium
| bisphasic - stroma & epithelium
| Other features
| Other features
| Radiology / gross
| tibia, fibula, intracortical, radiolucent
| Clinical
| Clinical
| IHC / other
| IHC / other
| Image
| [[Image:Adamantinoma_-_intermed_mag.jpg |thumb|center|150px|Adamantinoma. (WC)]]
|-
|-
| [[Diffuse tenosynovial giant-cell tumour]] ([[AKA]] [[PVNS]])
| [[Diffuse tenosynovial giant-cell tumour]] ([[AKA]] [[PVNS]])
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| Clinical
| Clinical
| IHC / other
| IHC / other
| Image
| [[Image:Pigmented_villonodular_synovitis_low_mag.jpg |thumb|center|150px| PVNS. (WC)]]
|-
|-
| [[Brown tumour]]
| [[Brown tumour]]
| Key feature
| fibrosis, +/-giant cells
| Other features
| unaffected bone incr. osteoblasts and osteoclasts
| Radiology / gross
| Radiology / gross
| due to hypercalcemia; not a neoplasm
| due to hypercalcemia; not a neoplasm
| IHC / other
| IHC / other
| Image
| [[Image:Brown_tumour_-_low_mag.jpg |thumb|center|150px| Brown tumour. (WC)]]
|-
|-
|}
|}


====Radiology====
====Radiology====
=====Radiologic features=====
{| class="wikitable sortable" style="margin-left:auto;margin-right:auto"
{| class="wikitable sortable" style="margin-left:auto;margin-right:auto"
| '''Features'''
! Features
| '''Benign'''
! Benign
| '''Malignant'''
! Malignant
|-
|-
| Bone changes
| Bone changes
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|}
|}


=Cartilage=
=====Location=====
==Chondroma==
{| class="wikitable sortable" style="margin-left:auto;margin-right:auto"
===General===
! Diagnosis
*Benign thingy.
! [[Epiphysis]]
*Usual legs and feet.
! [[Metaphysis]]
*May be difficult to separate from [[chondrosarcoma]].
! [[Diaphysis]]
*Multiple chondromas = ''enchondromatosis''; three distinct syndromes.<ref name=emed_enchondroma>URL: [http://emedicine.medscape.com/article/389224-overview http://emedicine.medscape.com/article/389224-overview]. Accessed on: 25 December 2010.</ref>
! Type of lesion
*''Enchondroma'' = chondroma in the marrow space.
|-
| [[Aneurysmal bone cyst]]
| common
| most common
| rare
| [[bone]]
|-
| [[Chondroblastoma]]
| most common
| rare
| extremely rare
| [[cartilage]]
|-
| [[Chondrosarcoma]]
| uncommon
| common
| most common
| [[cartilage]]
|-
| [[Chondromyxoid fibroma]]
| rare
| most common
| common
| other
|-
| [[Enchondroma]]
| rare
| common
| common
| [[cartilage]]
|-
| [[Ewing sarcoma]]
| rare
| common
| most common
| [[bone]]
|-
| [[Giant cell tumour of bone|Giant cell tumour]]
| most common
| rare
| extremely rare
| [[bone]]
|-
| Metastatic carcinoma
| rare
| common
| most common
| other
|-
| Non-ossifying fibroma
| extremely rare
| most common
| common
| other
|-
| [[Osteoblastoma]]
| rare
| most common
| uncommon
| [[bone]]
|-
| [[Osteochondroma]]
| extremely rare{{fact}} <!-- PMID 12873205 questions this -->
| most common
| common
| [[bone]]/[[cartilage]]
|-
| [[Osteoid osteoma]]
| uncommon
| common
| common<ref name=wheelessonline>URL: [http://www.wheelessonline.com/ortho/osteoid_osteoma http://www.wheelessonline.com/ortho/osteoid_osteoma]. Accessed on: 7 May 2012</ref>
| [[bone]]
|-
| [[Osteosarcoma]]
| rare
| most common
| uncommon
| [[bone]]
|}


Clinical:<ref name=emed_enchondroma>URL: [http://emedicine.medscape.com/article/389224-overview http://emedicine.medscape.com/article/389224-overview]. Accessed on: 25 December 2010.</ref>
How to remember the primary bone lesions:
*Pain.
#''Ewing sarcoma'' is the only malignant primary bone tumour of the diaphysis.
#''Giant cell tumour of bone'' is the only primary bone lesion of the epiphysis.
#The rest of the primary bone lesions are metaphyseal.
#*''Osteochondroma'' is bone first and cartilage second. It behaves like most primary bone lesions; it is usually metaphyseal.


===Radiology===
How to remember the primary cartilaginous lesions:
Features:<ref name=emed_enchondroma>URL: [http://emedicine.medscape.com/article/389224-overview http://emedicine.medscape.com/article/389224-overview]. Accessed on: 25 December 2010.</ref>
#''Chondroblastoma'' is epiphyseal. The chicken wire goes around the chicken coop.
*Lytic lesion.
#The others are diaphyseal.
*Usual close to a growth plate.


===Microscopic===
=Cartilage=
Features:
==Chondroma==
*Ctyologically benign cells is spaced nests.
{{Main|Chondroma}}
 
Images:
*[http://commons.wikimedia.org/wiki/File:Enchondroma_-_intermed_mag.jpg Enchondroma - intermed mag. (WC)].
*[http://commons.wikimedia.org/wiki/File:Enchondroma_-_very_high_mag.jpg Enchondroma - very high mag. (WC)].


==Chondroblastoma==
==Chondroblastoma==
===General===
{{Main|Chondroblastoma}}
*Growth plate lesion.
*Sclerotic margin.
*"Young" = growth plates open.
*Typically painful.<ref name=Ref_PCPBoD8_625>{{Ref PCPBoD8|625}}</ref>
 
===Gross===
*Well-defined lesion.
 
Image:
*[http://www.flickr.com/photos/35441329@N05/4052875138/in/set-72157622681280610 Chondroblastoma (flickr.com/humpath)].
 
===Microscopic===
Features:<ref name=Ref_WMSP_642>{{Ref WMSP|642}}</ref>
*Abundant extracellular material - pink on [[H&E stain]] - looks vaguely like cartilage.
*Chondroblasts:
**Nuclear morphology variable: ovoid, folded or grooved.
**Moderate-abundant eosinophilic cytoplasm.
*+/-Calcification surrounds the cell nests ("chickenwire" appearance) - '''classic feature'''.
**Cell nests have a thin pale blue rimming.
*+/-[[Giant cells]].
**May lead to confusion with ''[[giant cell tumour of bone]]''.
 
DDx:
*[[Giant cell tumour of bone]].
*[[Chondroma]].
*Well-differentiated [[chondrosarcoma]].
 
Images:
*[http://commons.wikimedia.org/wiki/File:Chondroblastoma_-_intermed_mag.jpg Chondroblastoma - intermed. mag. (WC)].
*[http://commons.wikimedia.org/wiki/File:Chondroblastoma_-_very_high_mag.jpg Chondroblastoma - very high mag. (WC)].
*[http://img.medscape.com/pi/emed/ckb/orthopedic_surgery/1230552-1254949-996.jpg Chondroblastoma (medscape.com)].<ref name=emed_chondroblastoma>URL: [http://emedicine.medscape.com/article/1254949-diagnosis http://emedicine.medscape.com/article/1254949-diagnosis]. Accessed on: 31 December 2010.</ref>
*[http://img.medscape.com/pi/emed/ckb/orthopedic_surgery/1230552-1254949-997.jpg Chondroblastoma with "chickenwire" appearance (medscape.com)].<ref name=emed_chondroblastoma>URL: [http://emedicine.medscape.com/article/1254949-diagnosis http://emedicine.medscape.com/article/1254949-diagnosis]. Accessed on: 31 December 2010.</ref>
*[http://path.upmc.edu/cases/case494/images/fig2a.jpg Chondroblastoma (upmc.edu)].<ref>URL: [http://path.upmc.edu/cases/case494.html http://path.upmc.edu/cases/case494.html]. Accessed on: 24 January 2012.</ref>
 
===IHC===
Features:<ref name=Ref_WMSP_642>{{Ref WMSP|642}}</ref>
*S100 +ve.
*Vimentin +ve.<ref name=emed_chondroblastoma>URL: [http://emedicine.medscape.com/article/1254949-diagnosis http://emedicine.medscape.com/article/1254949-diagnosis]. Accessed on: 31 December 2010.</ref>


==Chondromyxoid fibroma==
==Chondromyxoid fibroma==
===General===
{{Main|Chondromyxoid fibroma}}
*Benign.
*Teenagers or young adults.
 
===Gross===
*Metaphyseal lesion.
*Well-circumscribed.
 
===Microscopic===
Features:<ref name=Ref_WMSP642>{{Ref WMSP|642}}</ref>
*Spindle cells or stellate cells in a myxoid or chondroid stroma.
 
Images:
*[http://www.webpathology.com/image.asp?n=7&Case=331 Chondromyxoid fibroma - low mag. (webpathology.com)].
*[http://www.webpathology.com/image.asp?case=331&n=8 Chondromyxoid fibroma - high mag. (webpathology.com)].


==Chondrosarcoma==
==Chondrosarcoma==
===General===
{{Main|Chondrosarcoma}}
*Usually a good prognosis.
 
Clinical/epidemiologic features:<ref name=pmid17976362>{{cite journal |author=Skubitz KM, D'Adamo DR |title=Sarcoma |journal=Mayo Clin. Proc. |volume=82 |issue=11 |pages=1409–32 |year=2007 |month=November |pmid=17976362 |doi= |url=http://www.mayoclinicproceedings.com/content/82/11/1409.long}}</ref>
*Usually arise in a (benign) abnormality of cartilage (e.g. osteochondroma, enchondroma).
*May be associated with a syndrome:
**Olier disease (multiple enchondromatosis).
**Maffucci syndrome (multiple enchondromas and hemangiomas).
 
Notes:
*Review article (from oncology perspective): PMID 17545802.
 
====Subtypes====
Several subtypes exist:
*Chondrosarcoma not otherwise specified (NOS).
*Juxtacortical chondrosarcoma.
*Myxoid chondrosarcoma.
*Mesenchymal chondrosarcoma.
*Clear cell chondrosarcoma.
*Dedifferentiated chondrosarcoma.
 
===Microscopic===
Features:<ref>IAV. 26 February 2009.</ref><ref name=Ref_Klatt417>{{Ref Klatt|417}}</ref>
*"Abnormal cartilage":
**+/-Nuclear atypia - high grade lesions.
***High grade lesions:
****Nuclear clearing.
****Nucleoli.
****Hyperchromasia.
***Low/intermediate grade lesions:
****Bi-nucleation.
****Hypochromatic enlarged nuclei.
****Infiltration of lamellar bone ("invasion") - not common - '''diagnostic'''.
**Increased cellularity.
***More cellular than cartilage... but relatively paucicellular compared to other sarcomas.
**Irregular spacing of chondrocytes.
 
Notes:
*Low grade chondrosarcoma are not cytologically malignant; the diagnosis rests mostly on radiologic findings.
**The exception is ''infiltration of lamellar bone'' -- this is diagnostic of chondrosarcoma.<ref>BD. 28 April 2011.</ref>
 
DDx:
*[[Chordoma]].
*[[Enchondroma]].
*[[Synovial chondromatosis]].
*Chondroblastic [[osteosarcoma]] - has osteoid, may be focal.
 
Images:
*[[WC]]:
**[http://commons.wikimedia.org/wiki/File:Chondrosarcoma_(1).jpg Chondrosarcoma - low mag. (WC)].
**[http://commons.wikimedia.org/wiki/File:Chondrosarcoma_(2).jpg Chondrosarcoma - high mag. (WC)].
**[http://commons.wikimedia.org/wiki/File:Chondrosarcoma_(3).jpg Chondrosarcoma - high mag. (WC)].
*www:
**[http://path.upmc.edu/cases/case168.html Chondrosarcoma (upmc.edu)].
 
====Variants====
=====Mesenchymal chondrosarcoma=====
*Arise in soft tissue; this is where the name comes from.<ref name=pmid14161087>{{cite journal |author=Dowling EA |title=Mesenchymal chondrosarcoma |journal=J Bone Joint Surg Am |volume=46 |issue= |pages=747–54 |year=1964 |month=June |pmid=14161087 |doi= |url=http://www.ejbjs.org/cgi/reprint/46/4/747.pdf}}</ref>
*Rare variant of chondrosarcoma.
 
Microscopic:
Features:
*"White clouds in a blue sky".
 
Image:
*[http://moon.ouhsc.edu/kfung/jty1/opaq/PathQuiz/S0A001-PQ01-M.htm Mesenchymal chondrosarcoma (ouhsc.edu)].
 
=====Myxoid chondrosarcoma=====
Microscopic:
Features:
*[[Chordoma]]-like:
**[[Myxoid]] background.
**Small cells with eosinophilic cytoplasm.
 
DDx:
*Chondroid [[syringoma]].
*Parachordoma.<ref name=pmid10809219>{{cite journal |author=Fisher C |title=Parachordoma exists--but what is it? |journal=Adv Anat Pathol |volume=7 |issue=3 |pages=141–8 |year=2000 |month=May |pmid=10809219 |doi= |url=}}</ref>
*[[Chordoma]]. (???)
 
=====Extraskeletal myxoid chondrosarcoma=====
*Originally thought to be a variant of ''myxoid chondrosarcoma of bone''; however, may not be a chondrosarcoma at all.<ref name=pmid14657948>{{Cite journal  | last1 = Aigner | first1 = T. | last2 = Oliveira | first2 = AM. | last3 = Nascimento | first3 = AG. | title = Extraskeletal myxoid chondrosarcomas do not show a chondrocytic phenotype. | journal = Mod Pathol | volume = 17 | issue = 2 | pages = 214-21 | month = Feb | year = 2004 | doi = 10.1038/modpathol.3800036 | PMID = 14657948 | URL = http://www.nature.com/modpathol/journal/v17/n2/full/3800036a.html  }}</ref>
*Characteristic [[chromosomal translocation]]: t(9;22) CHN-EWS.
 
DDx:
*Chordoma.<ref name=pmid14657948/>
**S-100 +ve (strong).
**EMA +ve.
 
Image:
*[http://www.cttr.org/large/03113.jpg Extraskeletal myxoid chondrosarcoma (cttr.org)].<ref>URL: [http://www.cttr.org/cms/?p=736 http://www.cttr.org/cms/?p=736]. Accessed on: 1 May 2011.</ref>
 
=====Dedifferentiated chondrosarcoma=====
Clinical:
*Abysmal to poor prognosis.
**In one series (22 patients) 5-year survival ~20%.<ref>{{Cite journal  | last1 = Mitchell | first1 = AD. | last2 = Ayoub | first2 = K. | last3 = Mangham | first3 = DC. | last4 = Grimer | first4 = RJ. | last5 = Carter | first5 = SR. | last6 = Tillman | first6 = RM. | title = Experience in the treatment of dedifferentiated chondrosarcoma. | journal = J Bone Joint Surg Br | volume = 82 | issue = 1 | pages = 55-61 | month = Jan | year = 2000 | doi =  | PMID = 10697315 | URL = http://www.jbjs.org.uk/cgi/pmidlookup?view=long&pmid=10697315 }}</ref>
**All dead in two years in another series (25 patients).<ref name=pmid17653766/>
 
Features:<ref name=pmid17653766>{{Cite journal  | last1 = Sopta | first1 = J. | last2 = Dordević | first2 = A. | last3 = Tulić | first3 = G. | last4 = Mijucić | first4 = V. | title = Dedifferentiated chondrosarcoma: our clinico-pathological experience and dilemmas in 25 cases. | journal = J Cancer Res Clin Oncol | volume = 134 | issue = 2 | pages = 147-52 | month = Feb | year = 2008 | doi = 10.1007/s00432-007-0262-5 | PMID = 17653766 }}</ref>
#Poorly differentiated (mesenchymal) malignancy.
#Well-differentiated cartilaginous component.
 
Images:
*[http://path.upmc.edu/cases/case118/micro.html Dedifferentiated chondrosarcoma (upmc.edu)].
 
====Grading====
Features:<ref name=Ref_WMSP643>{{Ref WMSP|643}}</ref>
*Grade I: mild-to-moderate increase of cellularity +/- binucleated cells.
*Grade II: between Grade I and Grade III.
*Grade III: nuclear pleomorphism, mitoses common.
 
===IHC===
*S-100 -ve. (???)


=Bone=
=Bone=
==Osteoma==
==Osteoma==
===General===
{{Main|Osteoma}}
*Benign.
*May be associated with [[familial adenomatous polyposis]].
*Normal bone - unusual location/outgrowth.
 
===Microscopic===
Features:
*Normal bone.


==Osteoid osteoma==
==Osteoid osteoma==
===General===
{{Main|Osteoid osteoma}}
*Benign bone lesion.
 
Clinical:<ref name=Ref_Sternberg4_285>{{Ref Sternberg4|285}}</ref>
*Extremely painful.
**Relieved by NSAIDS.
 
===Microscopic===
Features:<ref name=Ref_Sternberg4_285>{{Ref Sternberg4|285}}</ref>
*Anastomosing bony [[trabeculae]] with:
**Variable mineralization.
***Mineralization (calcium '''p'''hosphate) = '''p'''urple on [[H&E stain]].
**Osteoblasts rimming.
***Cells line-up at edge of bone.
 
Note:
*Histomorphologically near identical/indistinguishable from ''[[osteoblastoma]]''.<ref name=Ref_Sternberg4_286>{{Ref Sternberg4|286}}</ref>
 
Images:
*[http://library.med.utah.edu/WebPath/COW/COW211.html Osteoid osteoma - CT scan (med.utah.edu)].
*[http://www.sciencephoto.com/images/imagePopUpDetails.html?pop=1&id=700030210&pviewid=&country=67&search=gschmeissners&matchtype=FUZZY Osteoid osteoma (sciencephoto.com)].
*[http://commons.wikimedia.org/w/index.php?title=File:Osteoid_osteoma_-_low_mag.jpg Osteoid osteoma - low mag. (WC)].
*[http://commons.wikimedia.org/w/index.php?title=File:Osteoid_osteoma_-_high_mag.jpg Osteoid osteoma - high mag. (WC)].


==Osteoblastoma==
==Osteoblastoma==
===General===
{{Main|Osteoblastoma}}
*Benign bone tumour.
 
===Microscopic===
Features:<ref name=Ref_Sternberg4_285>{{Ref Sternberg4|285}}</ref>
*Anastomosing bony [[trabeculae]] with:
**Osteoblasts rimming.
***Cells line-up at edge of bone.
 
Notes:
*Histomorphologically near identical/indistinguishable from ''[[osteoid osteoma]]''.<ref name=Ref_Sternberg4_286>{{Ref Sternberg4|286}}</ref>
*'''Must''' be greater 1.5 cm by definition.<ref name=Ref_Sternberg4_286>{{Ref Sternberg4|286}}</ref>
 
Images:
*[http://commons.wikimedia.org/w/index.php?title=File:Osteoblastoma_-_high_mag.jpg Osteoblastoma - high mag. (WC)].
*[http://commons.wikimedia.org/w/index.php?title=File:Osteoblastoma_-_low_mag.jpg Osteoblastoma - low mag. (WC)].


==Ewing sarcoma==
==Ewing sarcoma==
*[[AKA]] EWS/pPNET, AKA (confusingly) EWS/PNET:
{{Main|Ewing sarcoma}}
**EWS = Ewing sarcoma.
**pPNET = peripheral primitive neuroectodermal tumour.
*EWS and pPNET were once thought to be different tumours.
 
Notes:
*''Peripheral primitive neuroectodermal tumour'' should not be confused with ''[[primitive neuroectodermal tumour]]'', commonly abbreviated ''PNET'', a (supertentorial) brain tumour with similarities to [[medulloblastoma]].
 
===General===
Clinical:
*Painful.
*Usually younger than 20 years.
*Second most common malignant bone tumour in children.
**Most common malignant bone tumour = osteosarcoma (AKA osteogenic sarcoma).
 
Poor prognostic factors:<ref>PST. 14 February 2011.</ref>
*Age (18 years-old+).
*Pelvis (extremity = good).
*>8 cm.
*Metastases.
*EWS-FL1 fusion type 2.
*>90% necrosis.
 
Etiology:
*Unknown origin; hypothesis: Ewing sarcoma arises from mesenchymal stem cell.<ref name=pmid20953407>{{cite journal |author=Lin PP, Wang Y, Lozano G |title=Mesenchymal Stem Cells and the Origin of Ewing's Sarcoma |journal=Sarcoma |volume=2011 |issue= |pages= |year=2011 |pmid=20953407 |pmc=2952797 |doi=10.1155/2011/276463 |url=}}</ref>
 
====Radiology====
Features:<ref name=Ref_WMSP650>{{Ref WMSP|650}}</ref>
*Long bones, diaphyses.
*Destructive.
*"Onion-skin" periosteal reaction.
 
===Microscopic===
Features:<ref>PST. 22 February 2010.</ref>
*Scant clear cytoplasm (contain glycogen -- PAS +ve, PAS-D -ve) - '''key feature'''.
*Round small nucleus.
**Usu. lack nucleoli.
**Usu. minimal-moderate size variation.
*Mitoses (common).
 
Notes:
*It is a [[small round cell tumour]].
*[[Rhabdomyosarcoma]] occasionally has cytoplasmic clearing (due to glycogen).<ref name=PST14feb11>PST. 14 February 2011.</ref>
 
Images:
*[[WC]]:
**[http://commons.wikimedia.org/wiki/File:Ewing_sarcoma_-_very_high_mag.jpg ES - very high mag. (WC)].
**[http://commons.wikimedia.org/wiki/File:Ewing_sarcoma_-_PAS_-_very_high_mag.jpg ES - PAS - very high mag. (WC)].
*www:
**[http://path.upmc.edu/cases/case103.html Ewing sarcoma - case 1 - several images (upmc.edu)].
**[http://path.upmc.edu/cases/case420.html Ewing sarcoma - case 2 - several images (upmc.edu)].
 
===[[IHC]]===
Features:<ref name=Ref_WMSP651>{{Ref WMSP|651}}</ref>
*CD99 +ve -- 1. diffuse, 2. plasma membrane staining; both required -- most specific.
*FLI-1 +ve.<ref name=pmid15001993>{{cite journal |author=Rossi S, Orvieto E, Furlanetto A, Laurino L, Ninfo V, Dei Tos AP |title=Utility of the immunohistochemical detection of FLI-1 expression in round cell and vascular neoplasm using a monoclonal antibody |journal=Mod. Pathol. |volume=17 |issue=5 |pages=547–52 |year=2004 |month=May |pmid=15001993 |doi=10.1038/modpathol.3800065 |url=http://www.nature.com/modpathol/journal/v17/n5/full/3800065a.html}}</ref>
*CD45 -ve.
**Done to r/o [[lymphoma]].
*+/-Neural markers (NSE, synaptophysin, CD57 (??? CD56 ???), S100).
*+/-Cytokeratins.
*Caveolin-1 +ve in ~ 85% of EWS.<ref>PST. 14 February 2011.</ref>
*WT-1 -ve.<ref name=Ref_WMSP286>{{Ref WMSP|286}}</ref>
 
Notes:<ref>PST. 22 February 2010.</ref>
*CD99 +ve
**Plasma membrane staining tumours:
***[[Lymphoblastic lymphoma]]/leukemia.
***[[Angiomatoid fibrous histiocytoma]].
***[[Desmoplastic small round cell tumour]].
**Weak/cytoplasmic staining:
***[[Synovial sarcoma]].
***[[Rhabdomyosarcoma]].
***[[Rhabdoid tumour]].
*FLI-1 +ve:<ref name=pmid15001993/>
**Vascular neoplasms.
**-/+[[Merkel cell carcinoma]].
**-/+Melanoma.
 
===Molecular diagnostics===
Common features:
*''EWS/FLI-1 fusion gene'' formation due to [[translocation]]: ''t(11;22)(q24;q12)''.<ref>URL: [http://atlasgeneticsoncology.org/Tumors/Ewing5010.html http://atlasgeneticsoncology.org/Tumors/Ewing5010.html]. Accessed on: 23 February 2010.</ref><ref name=pmid3163261>{{cite journal |author=Turc-Carel C, Aurias A, Mugneret F, ''et al.'' |title=Chromosomes in Ewing's sarcoma. I. An evaluation of 85 cases of remarkable consistency of t(11;22)(q24;q12) |journal=Cancer Genet. Cytogenet. |volume=32 |issue=2 |pages=229–38 |year=1988 |month=June |pmid=3163261 |doi= |url=}}</ref>
**Often detected by RT-PCR (with EWS 5' and FLI-1 3' primers).
**Type 1 = EWS exon 7 + FLI-1 exon 6; good prognosis.
**Type 2 = others; poor prognosis.
 
Notes:
*The ''t(11;22)(q24;q12)'' is seen in ~90% of EWS/PNET... but also in:
**[[Olfactory neuroblastoma]].
**Small cell osteogenic sarcoma (small cell variant of [[osteosarcoma]]).
**Polyphenotypic tumours.
**[[Rhabdomyosarcoma]].
**[[Neuroblastoma]] (possibly).
*Several other EWS translocations exist.<ref>URL: [http://www.cancerindex.org/geneweb/EWSR1.htm http://www.cancerindex.org/geneweb/EWSR1.htm]. Accessed on: 20 November 2011.</ref>
**ERG,<ref name=omim165080>{{OMIM|165080}}</ref> ETV1, E1AF and FEV.
*Lack of molecular findings does ''not'' exclude Ewing sarcoma.
*Testing:
**A break apart probe for EWS is a common way to look for pathologic change, as it covers almost all variants.
 
===Electron microscopy===
*Primitive cell junctions.
*Clear zone (glycogen lakes).


==Osteosarcoma==
==Osteosarcoma==
*[[AKA]] osteogenic sarcoma.
{{Main|Osteosarcoma}}
 
===General===
*Most common malignant bone tumour in children.
*May be seen in the context of [[Li-Fraumeni syndrome]].
 
Trivia:
*Terry Fox was afflicited by this tumour.
 
====Definition====
*Tumour that makes osteoid.
**Osteoid = (extracellular) organic component of bone, normally produced by osteoblasts (cells which make bone matrix).
 
===Microscopic===
Features:
*Cells with malignant features (e.g. nuclear membrane irregularities, marked nuclear size differences, mitoses) surrounded by delicate strands of osteoid.
**Osteoid on H&E: pink, homogenous, "glassy".
**Tumours typically very cellular - when compared to normal bone.
*Large (multinucleated) osteoclast-like giant cells may be seen.<ref>{{cite journal |author=Papalas JA, Balmer NN, Wallace C, Sangueeza OP |title=Ossifying dermatofibroma with osteoclast-like giant cells: report of a case and literature review |journal=Am J Dermatopathol |volume=31 |issue=4 |pages=379-83 |year=2009 |month=June |pmid=19461244 |doi=10.1097/DAD.0b013e3181966747 |url=}}</ref>
 
Images:
*[http://commons.wikimedia.org/wiki/File:Osteosarcoma_-_intermed_mag.jpg Osteosarcoma - intermed. mag. (WC)].
*[http://commons.wikimedia.org/wiki/File:Osteosarcoma_-_very_high_mag.jpg Osteosarcoma - very high mag. (WC)].
*[http://commons.wikimedia.org/wiki/File:Small_cell_osteosarcoma_-_intermed_mag.jpg Small cell osteosarcoma - intermed. mag. (WC)].
*[http://commons.wikimedia.org/wiki/File:Small_cell_osteosarcoma_-_high_mag.jpg Small cell osteosarcoma - high mag. (WC)].
 
====Subtypes====
*Many subtypes exist.
 
Subclassification:<ref>{{Ref WMSP|638}}</ref><ref>URL: [http://bestpractice.bmj.com/best-practice/monograph/780/basics/classification.html http://bestpractice.bmj.com/best-practice/monograph/780/basics/classification.html]. Accessed on: 7 April 2011.</ref>
*Conventional osteosarcoma (high grade).
**Osteoblastic.
**Fibroblastic - [[undifferentiated pleomorphic sarcoma]]-like/[[MFH]]-like.
***Images: [http://path.upmc.edu/cases/case44.html Fibroblastic osteosarcoma (upmc.edu)].
**Chondroblastic - may be confused with [[chondrosarcoma]].
*Small cell - may mimic (other) [[small round cell tumours]].
*Telangiectatic - extremely vascular.
*Parosteal.
**Low grade.
**Arises from surface of bone.<ref>{{Ref WHOSTAB|279}}</ref>
*Periosteal.
*Low grade central.
*High grade surface.
*Secondary - arise due to something else (e.g. [[Paget disease of the bone]] (~80% of secondary osteosarcomas),  radiation (~15% of secondary osteosarcomas)).<ref>URL: [http://www.rsna.org/REG/publications/rg/afip/privateM/1997/0017/0005/1205/6.htm http://www.rsna.org/REG/publications/rg/afip/privateM/1997/0017/0005/1205/6.htm]. Accessed on: 8 April 2011.</ref>
**Images: [http://path.upmc.edu/cases/case598.html Secondary osteosarcoma - several images (upmc.edu)].
*Gnathic - jaw bones; usu. chondroblastic.
 
How to remember:
*Convention ''FOC'' = fibroblastic, osteogenic, chondroblastic.
*Low-grade central.
*High-grade surface.
*Parosteal.
*Periosteal.
*Small cell.
*Secondary.
*Telangiectatic.


==Giant cell tumour of bone==
==Giant cell tumour of bone==
===General===
{{Main|Giant cell tumour of bone}}
Features:<ref name=Ref_WMSP648>{{Ref WMSP|648}}</ref>
*Approximately 5% of primary bone tumours.
*Typical age: 20-45 years.
 
====Clinical====
*Location: growth plate of long bones.<ref name=pmid11501745>{{Cite journal  | last1 = Wülling | first1 = M. | last2 = Engels | first2 = C. | last3 = Jesse | first3 = N. | last4 = Werner | first4 = M. | last5 = Delling | first5 = G. | last6 = Kaiser | first6 = E. | title = The nature of giant cell tumor of bone. | journal = J Cancer Res Clin Oncol | volume = 127 | issue = 8 | pages = 467-74 | month = Aug | year = 2001 | doi =  | PMID = 11501745 }}</ref>
**May present with joint pain, immobility.
 
Note:
*Several types of [[giant cell lesions|giant cell tumours]] exist.
 
===Microscopic===
Features:<ref name=Ref_Klatt420>{{Ref Klatt|420}}</ref>
*Giant cells with a large number of nuclei (usu. >10 in the plane of section).
**Usu. have prominent nucleoli.
*Mononuclear cells and small multinucleated cells with nuclei similar to those in the giant cells - '''key feature'''.
 
Notes:
*Giant cells typically present in abundance.
 
DDx:
*[[Giant cell lesions]].
**[[Aneurysmal bone cyst]] - typically has spindle cells around the giant cells.
 
Images:
*[http://commons.wikimedia.org/wiki/File:Giant_cell_tumour_of_bone_-_high_mag.jpg GCT of bone - high mag. (WC)].
*[http://commons.wikimedia.org/wiki/File:Giant_cell_tumour_of_bone_-_low_mag.jpg GCT of bone - low mag. (WC)].
 
===IHC===
*p63 +ve in scattered mononuclear cells.<ref name=pmid18311114>{{cite journal |author=Dickson BC, Li SQ, Wunder JS, ''et al.'' |title=Giant cell tumor of bone express p63 |journal=Mod. Pathol. |volume=21 |issue=4 |pages=369–75 |year=2008 |month=April |pmid=18311114 |doi=10.1038/modpathol.2008.29 |url=}}</ref>
**This seems to be contradicted by another paper.<ref name=pmid20012988>{{cite journal |author=Alberghini M, Kliskey K, Krenacs T, ''et al.'' |title=Morphological and immunophenotypic features of primary and metastatic giant cell tumour of bone |journal=Virchows Arch. |volume=456 |issue=1 |pages=97–103 |year=2010 |month=January |pmid=20012988 |doi=10.1007/s00428-009-0863-2 |url=}}</ref>


=Other=
=Other=
This section collects stuff that doesn't neatly fit into the ''bone'' or ''cartilage'' category.
This section collects stuff that doesn't neatly fit into the ''bone'' or ''cartilage'' category.
==Osteochondroma==
===General===
*Benign.
*Usually metaphyseal lesions.
*Very common.
*Abnormal outgrowth of bone and cartilage.


===Microscopic===
==Notochordal tumors==
Features:
Notochordal tumors arise from notochordal remnants and thus are seen in the clivus or sacrum.
*Normal bone and cartilage.
{{Main|Chordoma}}


Images:
==Osteochondroma==
*[http://path.upmc.edu/cases/case341.html Super rare intracranial mesenchymal osteochondroma - several images (upmc.edu)].
{{Main|Osteochondroma}}


==Diffuse tenosynovial giant-cell tumour==  
==Diffuse tenosynovial giant-cell tumour==  
*[[AKA]] ''tenosynovial giant-cell tumour, diffuse type''.
*[[AKA]] ''tenosynovial giant-cell tumour, diffuse type''.
*Previously known as ''pigmented villonodular synovitis'' (PVNS).<ref>{{Ref PBoD8|1247}}</ref>  
*Previously known as ''pigmented villonodular synovitis'' (PVNS).<ref>{{Ref PBoD8|1247}}</ref>  
{{Main|Diffuse tenosynovial giant-cell tumour}}


===General===
==Giant cell tumour of tendon sheath==
*Course: benign.
*Abbreviated ''GCT of tendon sheath''.
*''Giant cell tumor of the tendon sheath'' is considered to be the soft-tissue counterpart of PVNS.<ref>URL: [http://emedicine.medscape.com/article/1253223-overview http://emedicine.medscape.com/article/1253223-overview]. Accessed on: 6 January 2011.</ref>
{{Main|Giant cell tumour of tendon sheath}}
 
===Microscopic===
Features:<ref>URL: [http://www.wheelessonline.com/ortho/pigmented_villonodular_synovitis http://www.wheelessonline.com/ortho/pigmented_villonodular_synovitis].</ref>
*Subsynovial nodules composed of cells with:
**Abundant cytoplasm.
**Pale nuclei.
*Multinucleated giant cells.
*Hemosiderin-laden macrophages.
*Foam cells.
 
Images:
*[[WC]]:
**[http://commons.wikimedia.org/wiki/File:Pigmented_villonodular_synovitis_low_mag.jpg PVNS - low mag. (WC)].
**[http://commons.wikimedia.org/wiki/File:Pigmented_villonodular_synovitis_high_mag.jpg PVNS - high mag. (WC)].
*www:
**[http://path.upmc.edu/cases/case251/micro.html PVNS - several images (upmc.edu)].


==Adamantinoma==
==Adamantinoma==
:Should '''not''' be confused with ''[[adenomatoid tumour]]''.
{{Main|Adamantinoma}}
===General===
Features:<ref name=Ref_WMSP650>{{Ref WMSP|650}}</ref>
*Rare: < 1% of bone tumours.
*25-35 years old.
*Tibia, fibula.
*Benign, may be locally aggressive.
*Cousin of [[ameloblastoma]]. (???)
 
===Radiology===
*Intracortical, radiolucent.
 
===Microscopic===
Features:
*Biphasic tumour:
*#Fibrous/spindle cell component.
*#Epithelial component.
 
Images:
*[http://southbaypath.org/CaseImages/sb5260/AdamantinomaBiopsy3.jpg Adamantinoma (southbaypath.org)].<ref>URL: [http://southbaypath.org/CaseImages/sb5260/sb5260.htm http://southbaypath.org/CaseImages/sb5260/sb5260.htm]. Accessed on: 7 December 2010.</ref>
*[http://commons.wikimedia.org/wiki/File:Adamantinoma_-_intermed_mag.jpg Adamantinoma - intermed. mag. (WC)].
 
DDx:<ref name=pathcon_adam>URL: [http://www.pathconsultddx.com/pathCon/diagnosis?pii=S1559-8675%2806%2970057-2 http://www.pathconsultddx.com/pathCon/diagnosis?pii=S1559-8675%2806%2970057-2]. Accessed on: 28 April 2011.</ref>
*Vascular tumours ([[Epithelioid hemangioendothelioma]]).
*Metastatic carcinoma.
 
===IHC===
Features:<ref name=pathcon_adam/>
*CK14 +ve (HMWK).<ref>URL: [http://www.nordiqc.org/Epitopes/Cytokeratins/cytokeratins.htm http://www.nordiqc.org/Epitopes/Cytokeratins/cytokeratins.htm]. Accessed on: 28 April 2011.</ref>
*CK19 +ve (LMWK).
*CK8/18 -ve (LMWK).


==Brown tumour==
==Brown tumour==
===General===
===General===
*''Not'' a true neoplasm,<ref name=pmid16775919>{{cite journal |author=Meydan N, Barutca S, Guney E, ''et al.'' |title=Brown tumors mimicking bone metastases |journal=J Natl Med Assoc |volume=98 |issue=6 |pages=950–3 |year=2006 |month=June |pmid=16775919 |pmc=2569361 |doi= |url=http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2569361/?page=1 }}</ref> i.e. the name is a misnomer.
*''Not'' a true neoplasm.<ref name=pmid16775919>{{cite journal |author=Meydan N, Barutca S, Guney E, ''et al.'' |title=Brown tumors mimicking bone metastases |journal=J Natl Med Assoc |volume=98 |issue=6 |pages=950–3 |year=2006 |month=June |pmid=16775919 |pmc=2569361 |doi= |url=http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2569361/?page=1 }}</ref>  
**If ''tumour'' is understood as a synonym for ''neoplasm'', the name is a misnomer.
**May (clinically) mimic a true neoplasm.
**May (clinically) mimic a true neoplasm.
*Due to hyperparathyroidism - usually [[parathyroid adenoma]].
*Due to hyperparathyroidism - usually [[parathyroid adenoma]].
Line 734: Line 370:


====Hypercalcemia DDx====
====Hypercalcemia DDx====
Mnemonic ''GRIMED'':<ref>TN06 Emerg.</ref>
Mnemonic ''GRIMED'':<ref>{{Ref TN2006 |Emerg.}}</ref>
*Granulomatous disease (tuberculosis, [[sarcoidosis]]).
*Granulomatous disease (tuberculosis, [[sarcoidosis]]).
*Renal disease.
*Renal disease.
Line 749: Line 385:
**Multinucleated cells (osteoclasts).
**Multinucleated cells (osteoclasts).
**Mononuclear cells around the bony trabeculae (osteoblasts).
**Mononuclear cells around the bony trabeculae (osteoblasts).


DDx:
DDx:
*[[Giant cell tumour of bone]] and other [[giant cell lesions]].
*[[Giant cell tumour of bone]] and other [[giant cell lesions]].


Images:
====Images====
*[http://path.upmc.edu/cases/case139/micro.html Brown tumour (upmc.edu)].
<gallery>
Image:Brown_tumour_-_low_mag.jpg | Brown tumour - low mag. (WC)
Image:Brown_tumour_-_intermed_mag.jpg | Brown tumour - intermed. mag. (WC)
Image:Brown_tumour_-_high_mag.jpg | Brown tumour - high mag. (WC)
</gallery>
www:
*[http://wwwold.path.utah.edu/classes/webpath/bonehtml/bone053.htm Brown tumour (utah.edu)].
*[http://www.mda-sy.com/pathology/BONEHTML/BONE054.HTM Brown tumour (mda-sy.com)].
*[http://path.upmc.edu/cases/case139/micro.html Brown tumour - several images (upmc.edu)].


=See also=
=See also=
Line 769: Line 412:
*[http://www.radiologyassistant.nl/en/494e15cbf0d8d Bone radiology (radiologyassistant.nl)].
*[http://www.radiologyassistant.nl/en/494e15cbf0d8d Bone radiology (radiologyassistant.nl)].


[[Category:Chondro-osseous tumours]]
[[Category:Weird stuff]]
[[Category:Weird stuff]]

Latest revision as of 01:46, 20 June 2016

A chondro-osseous tumour (osteosarcoma). H&E stain.

Chondro-osseous tumours occasionally cross the desk of the pathologist. They are grouped together as bone may develop from cartilage.

Primary bone tumours are rare; the most common bone tumour is metastases.[1]

Bone tumours occasionally are lumped with soft tissue tumours. Soft tissue tumours are dealt with in the soft tissue lesions article. An introduction to bone is found in the bone article. An introduction to cartilage is found in the cartilage article.

General

  • Diagnosis of a primary bone tumour should not be made without radiologic & clinical information!
  • Metastasis:primary bone tumours = >20:1.[1]

Common malignant

Epidemiology:[2]

  • Osteosarcoma -> 2nd decade.
  • Ewing's ->5-20 yrs.
  • Chondrosarcoma -> from enchondroma or osteochrondroma -- patients over 40 yrs.
  • Multiple myeloma -> most common primary bone tumour in adults.

Malignant bone tumours by age

Most common by age:[2]

Benign aggressive bone tumours

Ref.:[3][4]

Summary tables

Bone tumours

Entity Key feature Other features Radiology / gross Clinical Stains / other Image
Osteoma normal bone (???) other features (???) radiology / gross (???) ? no stains / may be assoc. with FAP
Osteoma. (WC)
Osteoid osteoma osteoblastic rimming anastomosing bony trabeculae must be <2 cm,[5] metaphysis painful, NSAIDs remove pain, young IHC / other
Osteoid osteoma. (WC)
Osteoblastoma osteoblastic rimming anastomosing bony trabeculae must be >1 cm,[5] often >=2 cm, metaphysis not painful IHC / other
Osteoblastoma. (WC)
Ewing sarcoma small round blue cell tumour cytoplasmic clearing (due to glycogen) usu. diaphysis pediatric, typically 1-10 years PAS+, PASD-, chromosomal translocations (usually t(11;22)(q24;q12))
Ewing sarcoma. PAS stain. (WC)
Osteosarcoma osteoid +/-hemorrhage, +/-cartilage distal femur, prox. tibia, prox. humerous typically 10-30 years, pain, swelling no stains; many subtypes
Osteosarcoma. (WC)
Giant cell tumour of bone abundant giant cells nuclei of surrounding cells similar to those in giant cells growth plate of long bones 20-45 years old, +/-joint pain, +/-immobility IHC / other
Giant cell tumour. (WC)

Cartilage tumours

Entity Key feature Other features Radiology / gross Clinical Stains / other Image
Chondroma ctyologically benign cells equally spaced nests usu. diaphysis benign / DDx: chondroma, well-diff. chondrosarcoma IHC / bone marrow cavity chondroma = enchondroma
Enchondroma. (WC)
Chondroblastoma abundant extracellular material, abundant eosinophilic cytoplasm calcifications surround cells nests ("chickenwire" appearance) - classic epiphysis DDx: giant cell tumour of bone S100+ve, vimentin +ve
Chondroblastoma. (WC)
Chondrosarcoma cartilaginous appearance +/- nuclear atypia lack osteoid, if present -> osteosarcoma usu. diaphysis, classically hip; almost never distal extremity >40 years old IHC / may be histologically benign looking
Chondrosarcoma. (WC)

Other

Entity Key feature Other features Radiology / gross Clinical Stains / other Image
Osteochondroma benign bone and cartilage Other features metaphyseal lesions Clinical IHC / other Image
Adamantinoma bisphasic - stroma & epithelium Other features tibia, fibula, intracortical, radiolucent Clinical IHC / other
Adamantinoma. (WC)
Diffuse tenosynovial giant-cell tumour (AKA PVNS) pigmented giant cells nodules Radiology / gross Clinical IHC / other
PVNS. (WC)
Brown tumour fibrosis, +/-giant cells unaffected bone incr. osteoblasts and osteoclasts Radiology / gross due to hypercalcemia; not a neoplasm IHC / other
Brown tumour. (WC)

Radiology

Radiologic features
Features Benign Malignant
Bone changes sclerotic rim tumour perforation
Circumscription pushing margins ill-defined/moth-eaten
Soft tissue involvement no common
Periosteal reaction no "hair-on-end" or "sunburst",
"onion skin", Codman's triangle
Location
Diagnosis Epiphysis Metaphysis Diaphysis Type of lesion
Aneurysmal bone cyst common most common rare bone
Chondroblastoma most common rare extremely rare cartilage
Chondrosarcoma uncommon common most common cartilage
Chondromyxoid fibroma rare most common common other
Enchondroma rare common common cartilage
Ewing sarcoma rare common most common bone
Giant cell tumour most common rare extremely rare bone
Metastatic carcinoma rare common most common other
Non-ossifying fibroma extremely rare most common common other
Osteoblastoma rare most common uncommon bone
Osteochondroma extremely rare[citation needed] most common common bone/cartilage
Osteoid osteoma uncommon common common[6] bone
Osteosarcoma rare most common uncommon bone

How to remember the primary bone lesions:

  1. Ewing sarcoma is the only malignant primary bone tumour of the diaphysis.
  2. Giant cell tumour of bone is the only primary bone lesion of the epiphysis.
  3. The rest of the primary bone lesions are metaphyseal.
    • Osteochondroma is bone first and cartilage second. It behaves like most primary bone lesions; it is usually metaphyseal.

How to remember the primary cartilaginous lesions:

  1. Chondroblastoma is epiphyseal. The chicken wire goes around the chicken coop.
  2. The others are diaphyseal.

Cartilage

Chondroma

Main article: Chondroma

Chondroblastoma

Main article: Chondroblastoma

Chondromyxoid fibroma

Main article: Chondromyxoid fibroma

Chondrosarcoma

Main article: Chondrosarcoma

Bone

Osteoma

Main article: Osteoma

Osteoid osteoma

Main article: Osteoid osteoma

Osteoblastoma

Main article: Osteoblastoma

Ewing sarcoma

Main article: Ewing sarcoma

Osteosarcoma

Main article: Osteosarcoma

Giant cell tumour of bone

Main article: Giant cell tumour of bone

Other

This section collects stuff that doesn't neatly fit into the bone or cartilage category.

Notochordal tumors

Notochordal tumors arise from notochordal remnants and thus are seen in the clivus or sacrum.

Main article: Chordoma

Osteochondroma

Main article: Osteochondroma

Diffuse tenosynovial giant-cell tumour

  • AKA tenosynovial giant-cell tumour, diffuse type.
  • Previously known as pigmented villonodular synovitis (PVNS).[7]
Main article: Diffuse tenosynovial giant-cell tumour

Giant cell tumour of tendon sheath

  • Abbreviated GCT of tendon sheath.
Main article: Giant cell tumour of tendon sheath

Adamantinoma

Main article: Adamantinoma

Brown tumour

General

  • Not a true neoplasm.[8]
    • If tumour is understood as a synonym for neoplasm, the name is a misnomer.
    • May (clinically) mimic a true neoplasm.
  • Due to hyperparathyroidism - usually parathyroid adenoma.
    • Usually secondary to chronic renal failure.

Hypercalcemia DDx

Mnemonic GRIMED:[9]

Microscopic

Features:

  • Fibrosis.
  • +/-Giant cells with round to oval nuclei and nucleoli.[10]
  • Bone unaffected by tumour - increased numbers of the following:
    • Multinucleated cells (osteoclasts).
    • Mononuclear cells around the bony trabeculae (osteoblasts).

DDx:

Images

  • Brown tumour - low mag. (WC)

  • Brown tumour - intermed. mag. (WC)

  • Brown tumour - high mag. (WC)

www:

See also

References

  1. ↑ 1.0 1.1 Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 632. ISBN 978-0781765275.
  2. ↑ 2.0 2.1 Yeung, J.C.; Leonard, Blair J. N. (2005). The Toronto Notes 2005 - Review for the MCCQE and Comprehensive Medical Reference (2005 ed.). The Toronto Notes Inc. for Medical Students Inc.. pp. OR42. ISBN 978-0968592854.
  3. ↑ Yeung, J.C.; Leonard, Blair J. N. (2005). The Toronto Notes 2005 - Review for the MCCQE and Comprehensive Medical Reference (2005 ed.). The Toronto Notes Inc. for Medical Students Inc.. pp. OR41. ISBN 978-0968592854.
  4. ↑ URL: http://www.emedicine.com/RADIO/topic494.htm.
  5. ↑ 5.0 5.1 Yalcinkaya, U.; Doganavsargil, B.; Sezak, M.; Kececi, B.; Argin, M.; Basdemir, G.; Oztop, F. (Dec 2014). "Clinical and morphological characteristics of osteoid osteoma and osteoblastoma: a retrospective single-center analysis of 204 patients.". Ann Diagn Pathol 18 (6): 319-25. doi:10.1016/j.anndiagpath.2014.08.006. PMID 25224389.
  6. ↑ URL: http://www.wheelessonline.com/ortho/osteoid_osteoma. Accessed on: 7 May 2012
  7. ↑ Kumar, Vinay; Abbas, Abul K.; Fausto, Nelson; Aster, Jon (2009). Robbins and Cotran pathologic basis of disease (8th ed.). Elsevier Saunders. pp. 1247. ISBN 978-1416031215.
  8. ↑ Meydan N, Barutca S, Guney E, et al. (June 2006). "Brown tumors mimicking bone metastases". J Natl Med Assoc 98 (6): 950–3. PMC 2569361. PMID 16775919. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2569361/?page=1.
  9. ↑ Shiau, Carolyn; Toren, Andrew (2006). Toronto Notes 2006: Comprehensive Medical Reference (Review for MCCQE 1 and USMLE Step 2) (22nd edition (2006) ed.). Toronto Notes for Medical Students, Inc.. pp. Emerg.. ISBN 978-0968592861.
  10. ↑ URL: http://path.upmc.edu/cases/case139/micro.html. Accessed on: 6 January 2012.

External links

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