Hodgkin lymphoma

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Hodgkin's lymphoma, abbreviated HL, is a malignancy that afflicts people in the prime of their life. Fortunately, it usually has a good prognosis.

Pathologists say "... it is both the easiest and hardest diagnosis to make." The reason for this is: the diagnosis depends on finding Reed-Sternberg cells; if they are obvious the diagnosis is easy... if you can't find 'em and an alternative diagnosis is not apparent -- you wonder whether you're missing them.

Clinical

Symptoms:[1]

  • Fever, night sweats, weight loss.
  • Infections (due to immune dysfunction).

Diagnosis:

  • HL cannot be diagnosed with standard flow cytometry (FC) - but has been diagnosed with specialized FC.[2]

HL subtypes

Types:[1]

  • Classical HL (CHL) - ~95% of HL.
  • Nodular lymphocyte-predominant HL (NLPHL) - ~5% of HL.

CHL

  • See microscopic for subtypes.

NLPHL

  • AKA lympho-histiocytic variant.
  • Abbreviated NLPHL.
  • Different IHC and morphologic appearance than classic HL.

Microscopic

By definition, HL has Reed-Sternberg cells (RSCs).

Classical HL

Features (classic HL):

  • Reed-Sternberg cell.
    • Large binucleated cell.
    • Macronucleolus - approximately the size of a RBC (~8 micrometers).
    • Well-defined cell border.

Images (classic HL):

Subtypes

There are four CHL subtypes:[1]

  1. Nodular sclerosis CHL - ~70% of CHL.
    • Mixed cellular background - T cell, plasma cells, eosinophils, neutrophils and histiocytes.
    • Nodular sclerosing fibrosis - thick strands fibrosis.
  2. Mixed cellularity CHL - ~20-25% of CHL.
    • Like nodular sclerosis - but no fibrosis.
  3. Lymphocyte-rich CHL - rare.
    • T lymphocytes only (no mix of cells).
  4. Lymphocyte-depleted CHL - rare.
    • Assoc. with HIV infection.

Memory device:

  • The subtypes prevalence is in reverse alphabetical order.

Nodular lymphocyte-predominant HL

Features (nodular lymphocyte-predominant Hodgkin's lymphoma):

  • Lymphocytic & histiocytic cell (L&H cell)[3] - variant of RSC:
    • Cells (relatively) small (compared to classic RSCs).
    • Lobulated nucleus - key feature.
    • Small nucleoli.

Image (NLPHL):

IHC

Abbreviated panel:[4]

  • CD30 Reed-Sternberg cells (RSCs) +ve ~98%
  • CD15 Reed-Sternberg cells +ve ~80%, stains neutrophils.
  • CD45 often negative in RSCs.
  • CD20 may stain RSCs.
  • PAX5 +ve.[5]

Additional - for completeness:

  • CD3 (T lymphocytes)

NLPHL IHC differs from the classical HL:[5]

  • LCA +ve.
  • CD20 +ve.
  • CD10 +ve.
  • Bcl-6 +ve.
  • EMA +ve.
  • CD30 -ve
  • CD15 -ve.

See also

References

  1. 1.0 1.1 1.2 Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 567. ISBN 978-0781765275.
  2. Fromm JR, Thomas A, Wood BL (March 2009). "Flow cytometry can diagnose classical hodgkin lymphoma in lymph nodes with high sensitivity and specificity". Am. J. Clin. Pathol. 131 (3): 322–32. doi:10.1309/AJCPW3UN9DYLDSPB. PMID 19228638.
  3. PMID: 9499174
  4. Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 568. ISBN 978-0781765275.
  5. 5.0 5.1 Lefkowitch, Jay H. (2006). Anatomic Pathology Board Review (1st ed.). Saunders. pp. 683. ISBN 978-1416025887.