Difference between revisions of "Lipoma"
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| Line 11: | Line 11: | ||
| IHC = S-100 +ve | | IHC = S-100 +ve | ||
| EM = | | EM = | ||
| Molecular = | | Molecular = MDM2/CDK4 amplification absent | ||
| IF = | | IF = | ||
| Gross = soft yellow tissue - typically with a thin capsule and lobulated | | Gross = soft yellow tissue - typically with a thin capsule and lobulated | ||
| Line 43: | Line 43: | ||
Note: | Note: | ||
*May be quite large ~10 cm. | *May be quite large ~10 cm. | ||
*Thigh lesions are more likely to the malignant than other sites.<ref name=pmid27020493/> | |||
==Microscopic== | ==Microscopic== | ||
| Line 97: | Line 98: | ||
Image:Yellow_adipose_tissue_in_paraffin_section_-_lipids_washed_out.jpg | Mature fat. (WC) | Image:Yellow_adipose_tissue_in_paraffin_section_-_lipids_washed_out.jpg | Mature fat. (WC) | ||
</gallery> | </gallery> | ||
==Molecular== | |||
*MDM2/CDK4 gene amplification absent. | |||
**Testing suggested in: lesions greater than 10 cm.<ref name=pmid27020493>{{Cite journal | last1 = Wong | first1 = DD. | last2 = Low | first2 = IC. | last3 = Peverall | first3 = J. | last4 = Robbins | first4 = PD. | last5 = Spagnolo | first5 = DV. | last6 = Nairn | first6 = R. | last7 = Carey-Smith | first7 = RL. | last8 = Wood | first8 = D. | title = MDM2/CDK4 gene amplification in large/deep-seated 'lipomas': incidence, predictors and clinical significance. | journal = Pathology | volume = 48 | issue = 3 | pages = 203-9 | month = Apr | year = 2016 | doi = 10.1016/j.pathol.2016.02.007 | PMID = 27020493 }}</ref> | |||
==Sign out== | ==Sign out== | ||
Revision as of 19:06, 19 August 2016
| Lipoma | |
|---|---|
| Diagnosis in short | |
 Mature adipose tissue (lipoma). H&E stain. | |
|
| |
| Synonyms | steatoma (old term, ambiguous) |
|
| |
| LM | mature adipocytes |
| LM DDx | liposarcoma, benign fat |
| IHC | S-100 +ve |
| Molecular | MDM2/CDK4 amplification absent |
| Gross | soft yellow tissue - typically with a thin capsule and lobulated |
| Site | soft tissue |
|
| |
| Prevalence | common |
| Prognosis | benign |
| Treatment | surgical removal or follow-up |
Lipoma is a benign adipocytic tumour.
General
- Benign.
- Several variants exist.
- Angiolipoma - one of the (classically) painful skin lesions.
- May be seen in association with MERRF syndrome (myoclonic epilepsy with ragged-red fibres).[1]
Gross
- Soft yellow tissue - typically lobulated and with a very thin capsule.
Note:
- May be quite large ~10 cm.
- Thigh lesions are more likely to the malignant than other sites.[2]
Microscopic
Features:
- Collection of mature adipocytes.
- Variation of size may be seen -- should prompt a search for lipoblasts.[3]
Notes:
- Microscopically not definitely distinguishable from mature clump of fat.
- The lesion must be labeled lipoma (by the clinican) to be signed-out as such.
DDx:
- Liposarcoma - increased number of blood vessels,[4] esp. chickenwire-like vessels, fibrous septae.
- Benign adipose tissue.
Images:
Variants
Angiolipoma
Microscopic:
- Numerous blood vessels present.
- +/-Microthrombi.
DDx:
Myolipoma
General:
Microscopic:[7]
- Mature adipose tissue.
- Benign smooth muscle - usually ~ 2x amount of fat.
Note:
- If skeletal muscle is present consider intramuscular lipoma.[9]
IHC:[7]
- Actin +ve.
- Desmin +ve.
Images:
Images
Lipoma - intermed. mag.
Lipoma - high mag.
Mature fat. (WC)
Molecular
- MDM2/CDK4 gene amplification absent.
- Testing suggested in: lesions greater than 10 cm.[2]
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SUBCUTANEOUS TISSUE ("LIPOMA"), LEFT AXILLA, EXCISION:
- MATURE ADIPOSE TISSUE CONSISTENT WITH LIPOMA.
LESION ("LIPOMA"), SPERMATIC CORD (LATERALITY NOT SPECIFIED), EXCISION:
- MATURE ADIPOSE TISSUE CONSISTENT WITH LIPOMA.
Colonic lipoma (clinically suspected)
B. SIGMOID COLON AT 55 CM, BIOPSY: - COLORECTAL-TYPE MUCOSA WITHIN NORMAL LIMITS WITH A SMALL AMOUNT OF SUBMUCOSAL ADIPOSE TISSUE; COMPATIBLE WITH CLINICAL IMPRESSION OF LIPOMA.
Mirco
The sections show mature adipocytes. There is no increase in vascularity. No thick fibrous septa are present.
See also
References
- ↑ Jones, AP.; Lewis, CJ.; Dildey, P.; Hide, G.; Ragbir, M. (Jan 2012). "Lipoma or liposarcoma? A cautionary case report.". J Plast Reconstr Aesthet Surg 65 (1): e11-4. doi:10.1016/j.bjps.2011.08.004. PMID 21865105.
- ↑ 2.0 2.1 Wong, DD.; Low, IC.; Peverall, J.; Robbins, PD.; Spagnolo, DV.; Nairn, R.; Carey-Smith, RL.; Wood, D. (Apr 2016). "MDM2/CDK4 gene amplification in large/deep-seated 'lipomas': incidence, predictors and clinical significance.". Pathology 48 (3): 203-9. doi:10.1016/j.pathol.2016.02.007. PMID 27020493.
- ↑ Mentzel, T.; Fletcher, CD. (1995). "Lipomatous tumours of soft tissues: an update.". Virchows Arch 427 (4): 353-63. PMID 8548119.
- ↑ Yang, YJ.; Damron, TA.; Cohen, H.; Hojnowski, L. (Oct 2001). "Distinction of well-differentiated liposarcoma from lipoma in two patients with multiple well-differentiated fatty masses.". Skeletal Radiol 30 (10): 584-9. doi:10.1007/s002560100395. PMID 11685482.
- ↑ Friedberg, MK.; Chang, IL.; Silverman, NH.; Ramamoorthy, C.; Chan, FP. (May 2006). "Images in cardiovascular medicine. Near sudden death from cardiac lipoma in an adolescent.". Circulation 113 (21): e778-9. doi:10.1161/CIRCULATIONAHA.105.589630. PMID 16735681. http://circ.ahajournals.org/content/113/21/e778.full.
- ↑ URL: http://www.webmedcentral.com/article_view/1878. Accessed on: 14 March 2013.
- ↑ 7.0 7.1 7.2 Murphey, MD.; Carroll, JF.; Flemming, DJ.; Pope, TL.; Gannon, FH.; Kransdorf, MJ.. "From the archives of the AFIP: benign musculoskeletal lipomatous lesions.". Radiographics 24 (5): 1433-66. doi:10.1148/rg.245045120. PMID 15371618. http://radiographics.rsna.org/content/24/5/1433.long.
- ↑ Meis, JM.; Enzinger, FM. (Feb 1991). "Myolipoma of soft tissue.". Am J Surg Pathol 15 (2): 121-5. PMID 1703396.
- ↑ URL: http://surgpathcriteria.stanford.edu/softfat/lipoma/intramuscular_lipoma.html. Accessed on: 14 March 2013.
- ↑ Lee, YS.; Park, SE.; Lee, JU.; Choi, ES.. "MRI of a subcutaneous myolipoma in the ankle: a case report.". Korean J Radiol 12 (5): 641-5. doi:10.3348/kjr.2011.12.5.641. PMC 3168809. PMID 21927569. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3168809/.