Anaplastic large cell lymphoma

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Anaplastic large cell lymphoma, abbreviated ALCL, is an uncommon large cell lymphoma.

Anaplastic large cell lymphoma
Diagnosis in short

Anaplastic large cell lymphoma. H&E stain.

LM large cells with eosinophilic cytoplasm, Hallmark cells ("horseshoe-shaped or donut-shaped nucleus + eosinophilic paranuclear region")
LM DDx Hodgkin's lymphoma, poorly differentiated carcinoma
IHC CD30 +ve, ALK-1 -ve/+ve, CD45 +ve, CD4 +ve, CD3 -ve/+ve, CD7 -ve/+ve, EMA +ve
Molecular t(2,5)(p23;q35)
Site skin, lymph node, other

Prevalence uncommon
Prognosis good to poor, dependent on ALK status and site

General

  • May look a lot like a carcinoma.
    • Often subcapsular in LNs.
  • Usually T-cell derived.
  • May be isolated to the skin - good prognosis.

Subtypes:

  • Systemic ALCL.
  • Cutaneous ALCL -- ALK -ve.

ALK IHC - systemic form:

  • +ve = good prognosis (generally a disease of children, teenagers and young adults)
  • -ve = bad prognosis

Microscopic

Features:

  • Large cells with eosinophilic cytoplasm.
  • Usually appear cohesive.
  • May be subcapsular in a lymph node and mimic a carcinoma.
  • Hallmark cells = "horseshoe-shaped or donut-shaped nucleus + eosinophilic paranuclear region"[1][2] - key feature.
    • The donut-shaped version is also known as a "wreath cell"[3] - large (multi-nucleated) cells with (morphologically) one toroidal-shaped nucleus.
  • ALK+ ALCL includes variants without the classical hallmark cells, e.g. small cell variant and lymphohistiocytic variant

DDx:

  • Hodgkin's lymphoma
  • Anaplastic variants of other haematolymphoid malignancies, e.g. DLBCL or myeloma
  • Carcinoma
  • Melanoma

Images

www:

IHC

Features:

  • CD30 +ve (usually strong and diffuse)
  • ALK-1 -ve/+ve; strongly supports ALCL Dx if +ve.
  • CD45 +ve.
  • CD4 +ve.
  • CD3 -ve/+ve.
  • CD7 -ve/+ve.
  • EMA +ve.
  • Cytotoxic markers (e.g. TIA, perforin)

Molecular

  • In ALK+ ALCL, there is commonly an ALK1 rearrangement.
    • This may be ALK::NPM1, i.e. t(2,5)(p23;q35)[4] - combined nuclear and cytoplasmic ALK staining is a surrogate for this translocation.
  • Other non-NPM1 partners may occur. A ALK1 break-apart probe will detect these.

See also

References

  1. Rapkiewicz, A.; Wen, H.; Sen, F.; Das, K. (Dec 2007). "Cytomorphologic examination of anaplastic large cell lymphoma by fine-needle aspiration cytology.". Cancer 111 (6): 499-507. doi:10.1002/cncr.23120. PMID 17941004. http://onlinelibrary.wiley.com/doi/10.1002/cncr.23120/full.
  2. Ponzoni, M.; Terreni, MR.; Ciceri, F.; Ferreri, AJ.; Gerevini, S.; Anzalone, N.; Valle, M.; Pizzolito, S. et al. (Nov 2002). "Primary brain CD30+ ALK1+ anaplastic large cell lymphoma ('ALKoma'): the first case with a combination of 'not common' variants.". Ann Oncol 13 (11): 1827-32. PMID 12419758.
  3. Amin, HM.; Lai, R. (Oct 2007). "Pathobiology of ALK+ anaplastic large-cell lymphoma.". Blood 110 (7): 2259-67. doi:10.1182/blood-2007-04-060715. PMID 17519389. http://bloodjournal.hematologylibrary.org/content/110/7/2259.full.html.
  4. Lamant L, Meggetto F, al Saati T, et al. (January 1996). "High incidence of the t(2;5)(p23;q35) translocation in anaplastic large cell lymphoma and its lack of detection in Hodgkin's disease. Comparison of cytogenetic analysis, reverse transcriptase-polymerase chain reaction, and P-80 immunostaining". Blood 87 (1): 284–91. PMID 8547653.