Lymphoma & related disorders
Splenic hematogenous neoplasms
Hairy cell leukemia

Topic Completed: 1 January 2013

Minor changes: 1 April 2020

Copyright: 2003-2020,, Inc.

PubMed Search: Hairy cell leukemia[TI] spleen[TIAB] full text[sb]

See also: Variant type

Page views in 2019: 1,097
Page views in 2020 to date: 770
Cite this page: Mansouri J. Hairy cell leukemia. website. Accessed August 6th, 2020.
Definition / general
  • Rare; formerly known as leukemic reticuloendotheliosis; hairy cells may represent activated memory cells
  • Older (mean age 50 years) white men (80% men) with pancytopenia (50%), massive splenomegaly with obliteration of white pulp and involvement of red pulp (common), infections (30%)
  • Chronic leukemia with splenomegaly (1 kg) and minimal lymphadenopathy; associated with frequent atypical mycobacterial infection with monocytopenia, weakness, weight loss
Case reports
  • Splenectomy, 2-chlorodeoxyadenosine, interferon; cause apparent cures
Gross description
  • Diffuse and marked enlargement of spleen without nodules
Microscopic (histologic) description
  • Red pulp involvement by bland tumor cells larger than small lymphocytes, with modest, pale blue agranular cytoplasm with threadlike extensions seen with phase contrast microscope, round or folded nuclei, no distinct nucleoli
  • Residual follicles often present
  • No / rare mitotic figures
  • No phagocytosis
  • Also increase in volume, surface and length of red pulp arterial vessels, pools (lakes) of blood in red pulp lined by hairy cells and simulating dilated sinuses or hemangiomas
  • Tumor cells may aggregate in subendothelial spaces of trabecular veins
  • White pulp may be atrophic or obliterated
  • May have extramedullary hematopoiesis or large necrotizing granulomas secondary to atypical mycobacterial infection

Bone marrow:
  • Acellular aspirate due to reticulin fibers
  • "Fried egg" appearance of hairy cells, which have abundant cytoplasm, distinct cell borders, bland round or oval nuclei
  • Extravasated red blood cells common
  • Mast cells also common
Microscopic (histologic) images

Images hosted on other servers:

Figure 1

Bone marrow aspirate

Positive stains
Negative stains
Electron microscopy description
  • Prominent cytoplasmic villous projections
Molecular / cytogenetics description
Molecular / cytogenetics images

Images hosted on other servers:

mutation - HCL /
other peripheral
B cell neoplasms

Back to top