Clinico-pathological and Immunophenotype Analysis of Hairy Cell Leukemia Cases – A Single Institute Experience

ABSTRACT

Background: Hairy cell leukemia is a mature lymphoid B cell disorder, characterized by hairy cells, a specific genetic profile, different clinical course and the need for an appropriate treatment. It is seen primarily in elderly, characterized by a triad of splenomegaly, pancytopenia and monocytopenia. Aim: To evaluate clinicopathologically and with immunophenotyping hairy cell leukemia cases received at our institute in conjunction with similar studies. Material and methods: This is a retrospective study which included 7 cases over a period of 3 years (2019-2021) confirmed on morphology and flow cytometry. Results: The study revealed 7 cases which showed patients with age ranging from 34-65 years. MF ratio was 61. Two cases were covid positive (28.5%). Most of the cases presented with fever, weakness (28.5%). Splenomegaly was seen in three of the cases (42.6%). Laboratory investigations revealed anemia in 71% cases, leucopenia in 56.8%, lymphocytic prominence in 100% and pancytopenia in 14.2%. One patient presented with leukocystosis (14.2%). Marrow was hemodiluted and aparticulate in 3(42.6%) cases. Hairy cells were seen on morphology of peripheral smear and marrow aspirate. On flow cytometry, CD5 negative in all cases (100%), CD10 positive in 2(28.5%) and CD23 in 2 cases (28.5%). Few cases confirmed BRAF v600e mutations. Conclusion: Unusual findings like leukocytosis, absence of spleen, presence of lymphadenopathy can be present in hairy cell leukemia. Classical fried egg appearance in trephine biopsy may not be afeature in all the cases. CD123 is expressed in covid patients unlike other studies and further research is needed to establish the loss of CD123 in covid patients.