Image Question-20

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What is the diagnosis?

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This picture is a contribution of Paulo Henrique Orlandi Mourao (https://creativecommons.org/licenses/by-sa/3.0/deed.en).

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Hairy cell leukemia usually classified as a subtype of

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A. Acute myeloid leukemia
B. Chronic lymphocytic leukemia
C. Acute lymphocytic leukemia
D. Chronic myeloid leukemia

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Hairy cell leukemia is accumulation of abnormal –

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A. Cytotoxic T Cells

B. Helper T Cells

C. Memory T Cells

D. B lymphocytes

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Which is the most common physical finding in hairy cell leukemia?

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A. Hepatomegaly

B. Lymphadenopathy

C. Splenomegaly

D. Pedal edema

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Commonest sites of involvement in hairy cell leukemia?

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 A. liver

B. lymph node

C. skin

D. bone marrow

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In-Shorts

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Interleukin-2 receptor –

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Hairy cells express and secrete an immune system protein called interleukin-2 receptor (IL-2R).

The level increases as hairy cells proliferate, and decreases when they are killed.

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Classification of hairy cell leukemia

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1. Hairy cell leukemia-classic
2. Hairy cell leukemia-variant
3. Hairy cell leukemia-Japanese variant 

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Tartrate-resistant acid phosphatase (TRAP) stain-

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Tartrate does not inactivate the enzyme acid phosphatase within the neoplastic cells in hairy cell leukemia – because they are tartrate-resistant.

This is a feature not seen in most other leukemias and lymphomas. This is seen in hairy cell leukemia.

With tartrate-resistant acid phosphatase (TRAP) stain, the hairy cells show red granular cytoplasmic staining.

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Nowadays, the TRAP cytochemistry has been largely replaced by TRAP immunohistochemistry (shown here). It must be remembered that TRAP immunostains are not as specific as TRAP cytochemistry and may stain other B-cell neoplasms.

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