Lymph node pathology

From Libre Pathology
Revision as of 15:46, 3 August 2010 by Michael (talk | contribs) (+toxo)
Jump to navigation Jump to search

This article deals with lymph node pathology. An introduction to the lymph node is in the lymph nodes article.

Progressive transformation of germinal centers

General

  • Abbreviated as PTGC.
  • Benign.
  • Classically in younger patients.
  • Associated with Hodgkin's lymphoma - non-classic type (nodular lymphocyte predominant Hodgkin's lymphoma).

Microscopic

Features:

  • Large germinal centers - focally.
    • No mass lesions.

Reactive follicular hyperplasia

General

  • Many causes - including: bacteria, viruses, chemicals, drugs, allergens.
    • In only approximately 10% can definitive cause be identified.[1]

Microscopic

Features:[2]

  • Enlarged follicles, follicle size variation - key feature with:
    • Large germinal centers (pale on H&E).
      • Mitoses common.
      • Variable lymphocyte morphology.
      • Tingible-body macrophage (large, pale cells with junk in the cytoplasm).
    • Rim of small (inactive) lymphocytes.

IHC:

  • BCL-2 -ve.

Image: Normal lymph node (umdnj.edu).

Diffuse paracortical hyperplasia

General

  • Benign.

Microscopic

Features:[2]

  • Interfollicular areas enlarged - key feature.
    • T cell population increased.
    • Plasma cells.
    • Macrophages.
    • Large Reed-Sternberg-like cells.

Sinus histiocytosis

General

  • Benign.

Microscopic

Features:[2]

  • Sinuses distended with histiocytes - key feature.
  • Plasma cells increased.

Kikuchi disease

General

  • AKA histiocytic necrotising lymphadenitis (HNL),[3] and Kikuchi-Fujimoto disease.
  • Rare disease that may mimic cancer, esp. lymphoma.
    • May cause fever & systemic symptoms.[4]

Epidemiology:[4]

  • Usually <40 years old.
  • Asian.
  • Female:Male = 3:1.[5]

Treatment:

  • Usually self-limited.[4]
  • Oral corticosteroids.

DDx:

  • Non-Hodgkin lymphoma.
  • Systemic lupus erythematosus.

Micrograph

Features (the three main features - just as the name suggests):[6]

  • Histiocytes.
    • May be crescentic.
  • Necrosis (due to apoptosis) - paracortical areas.[4]
    • Necrosis without neutrophils - key feature.
  • Lymphocytes (CD8 +ve).
  • Plasmacytoid dendritic cells.


Notes:

  • Dendritic cell - vaguely resembles a macrophage:[7]
    • Long membrane projections - key feature.
    • Abundant blue-grey cytoplasm, +/- ground-glass appearance.
    • Nucleus: small, ovoid, usu. single nucleolous.

Images:

IHC

  • CD68 +ve.
  • CD8 +ve.
  • CD4, CD20, CD3, and CD30 - mixed.
    • Done to excluded lymphoma; should show a mixed population of lymphocytes.

Castleman disease

General

  • AKA angiofollicular lymph node hyperplasia, giant lymph node hyperplasia.[8]
  • Benign.
  • Abbreviated CD.

Classification

CD is grouped by location/involvment:

  • Hyaline vascular variant.
    • Usually unicentric.
    • Typically mediastinal or axial.
  • Plasma cell variant.
    • Usually multicentric.
    • Abundant plasma cells.
    • Associated with HHV-8 infection (the same virus implicated in Kaposi's sarcoma).

Discussed here: [9]

Microscopic

Features:[10]

  • Pale concentric (expanded) mantle zone lymphocytes.
    • "Regressed follicle". (???)
  • "Lollipops" - germinal centers fed by prominent vessels; lollipop-like appearance.
  • Two germinal centers in one follicle.

Cat-scratch disease

General

  • AKA Cat-scratch fever.
  • Infection caused Bartonella henselae,[11] a gram-negative bacilla (0.3-1.0 x 0.6-3.0 micrometers) in chains, clumps, or singular.[12]
  • Treatment: antibiotics.

Clinical

Features:[13]

  • Usually unilateral.
    • May be desseminated in individuals with immune dysfunction.
  • Contact with cats.

Micrograph

Features:[13]

  • Necrotizing granulomas with:
    • Neutrophils present in microabscess (necrotic debris) - key feature.
      • Microabscesses often described as "stellate" (star-shaped).
  • +/-Multinucleated giant cells.

Notes:

  • May involve capsule or perinodal tissue.

Stains:

  • Warthin-Starry stain +ve.
  • B. henselae IHC stain +ve.

Image(s):

Toxoplasma lymphadenitis

General

  • Caused by protozoan Toxoplasma gondii.

Microscopic

Features:[13]

  • Reactive germinal centers (pale areas - larger than usual).
  • Epithelioid cells - perifollicular & intrafollicular.
    • Loose aggregates of histiocytes (do not form round granulomas):
      • Abundant pale cytoplasm.
      • Nucleoli.
  • Monocytoid cells (monocyte-like cells) - in cortex & paracortex.
    • Large cells in islands/sheets key feature with:
      • Abundant pale cytoplasm - important.
      • Well-defined cell border - important.
      • Singular nucleus.

Notes:

  • Monocytoid cells CD68 -ve.

Dermatopathic lymphadenopathy

General

  • Lymphadenopathy associated with a skin lesion. (???)
  • May be benign of malignant (e.g. T-cell lymphoma).

Microscopic

  • May see melanin pigment. (???)

See also

References

  1. ↑ Ioachim, Harry L; Medeiros, L. Jeffrey (2008). Ioachim's Lymph Node Pathology (4th ed.). Lippincott Williams & Wilkins. pp. 174. ISBN 978-0781775960.
  2. ↑ 2.0 2.1 2.2 Ioachim, Harry L; Medeiros, L. Jeffrey (2008). Ioachim's Lymph Node Pathology (4th ed.). Lippincott Williams & Wilkins. pp. 179. ISBN 978-0781775960.
  3. ↑ Kaushik V, Malik TH, Bishop PW, Jones PH (June 2004). "Histiocytic necrotising lymphadenitis (Kikuchi's disease): a rare cause of cervical lymphadenopathy". Surgeon 2 (3): 179–82. PMID 15570824.
  4. ↑ 4.0 4.1 4.2 4.3 Hutchinson CB, Wang E (February 2010). "Kikuchi-Fujimoto disease". Arch. Pathol. Lab. Med. 134 (2): 289–93. PMID 20121621.
  5. ↑ URL: http://emedicine.medscape.com/article/210752-overview. Accessed on: 3 June 2010.
  6. ↑ URL: http://www.ispub.com/journal/the_internet_journal_of_head_and_neck_surgery/volume_1_number_1_30/article_printable/kikuchi_s_lymphadenitis_in_a_young_male.html. Accessed on: 1 June 2010.
  7. ↑ URL: http://www.healthsystem.virginia.edu/internet/hematology/hessedd/benignhematologicdisorders/normal-hematopoietic-cells/dendritic-cell.cfm?drid=214. Accessed on: 3 June 2010.
  8. ↑ URL: http://www.mayoclinic.com/health/castleman-disease/DS01000. Accessed on: 17 June 2010.
  9. ↑ PMID 19546611
  10. ↑ URL: http://www.ispub.com/journal/the_internet_journal_of_otorhinolaryngology/volume_9_number_2_11/article/a_rare_case_of_castleman_s_disease_presenting_as_cervical_neck_mass.html. Accessed on: 15 June 2010.
  11. ↑ Jerris, RC.; Regnery, RL. (1996). "Will the real agent of cat-scratch disease please stand up?". Annu Rev Microbiol 50: 707-25. doi:10.1146/annurev.micro.50.1.707. PMID 8905096.
  12. ↑ Ioachim, Harry L; Medeiros, L. Jeffrey (2008). Ioachim's Lymph Node Pathology (4th ed.). Lippincott Williams & Wilkins. pp. 110. ISBN 978-0781775960.
  13. ↑ 13.0 13.1 13.2 Ioachim, Harry L; Medeiros, L. Jeffrey (2008). Ioachim's Lymph Node Pathology (4th ed.). Lippincott Williams & Wilkins. pp. 113. ISBN 978-0781775960.
Retrieved from "https://librepathology.org/w/index.php?title=Lymph_node_pathology&oldid=1206"