Secondary Lymphoid Tissues ›› Spleen ›› Abnormal

Hairy Cell Leukemia*






Microscopic Features:
  • Peripheral blood smear shows abnormal intermediate-sized lymphocytes with hair-like cytoplasmic projections
  • Prominent nucleolus
Normal % blood-PB, marrow-BM, lymphoid tissue-LN:
  • PB: None
  • BM: None
  • LN: None
May Resemble:
  • Splenic Marginal Zone Lymphoma
  • Reactive lymphocyte
  • CLL
Differential Diagnoses:

Splenic Marginal Zone Lymphoma
Reactive Lymphocytosis
CLL

Classic Immunophenotype:
  • CD19+
  • CD20+
  • CD5-
  • CD10-
  • CD103+
  • CD11c+
  • CD25+
  • Annexin1+
Cartoon Image:



Misc:
  • Splenomegaly, Pancytopenia (many with monocytopenia), and dry aspirate during biopsy (due to marrow fibrosis) are common findings The neoplastic cells typically involve the red pulp area of the spleen (as opposed to Splenic Marginal Zone Lymphoma which involves the white pulp)