What is hairy cell leukemia ?
Hairy cell leukemia (HCL) is a slow-growing cancer of mature B cells, characterized by abnormal cells with abundant cytoplasm and distinctive hair-like projections.
What are the sites of hairy cell leukemia?
-It typically affects the bone marrow, peripheral blood, and spleen.
What is the clinical presentation ?
– Fatigue, fever, opportunistic infections, bleeding, discomfort or pain in the upper-left quadrant, night sweats, Hepatomegaly, lymphadenopathy.
Rare symptoms– paraneoplastic/autoimmune vasculitis, arthritis, dermatitis, or neuropathy
What is the etiopathogenesis of Hairy cell leukemia?
-Over representation of the HLA-DRB*11,
-Farming and exposure to pesticides have been associated with an increased risk of HCL
-High exposure to benzene may also be a risk factor
-Activating BRAF p.V600E mutation
What are the laboratory findings??
–Complete blood count and peripheral smear shows pancytopenia and monocytopenia.
–Peripheral Blood smear study shows circulating neoplastic hairy cells with villous projections.
These cells are small to medium sized lymphoid cells ( 10-20 micrometer in diameter) with abundant pale blue or blue-gray cytoplasm. The nucleus is often eccentrically placed, reniform and with loose chromatin. The nucleoli is inconspicuous or absent. Fine, shaggy irregular projections are seen in the cytoplasm circumferentially and hence the name ‘hairy cell”
Bone marrow Aspiration/ biopsy– Usually a dry tap due to extensive fibrosis.
Bone marrow biopsy reveals similar neoplastic cells as seen in peripheral smear. At low power these neoplastic cells gives an appearance of “fried egg”.
What are the other organs involved in case of HCL?
Red pulp infiltration of the spleen, Sinusoidal infiltration of the liver and in case of advanced disease interfollicular and paracortical areas of lymph nodes are also involved
what is the treatment of HCL ?
Chemotherapy with purine analogues (cladribine and pentostatin) is highly effective as a first line treatment for HCL.
–
