Haematological profile of 21 patients with hairy cell leukaemia in a tertiary care centre of north India

Background & objectives: Hairy cell leukaemia (HCL) is a B cell neoplasm which constitutes around 2 per cent of all the lymphoid leukaemias. It has a characteristic morphology and immunophenotypic profile. It is important to distinguish HCL from other B cell lymphoproliferative disorders due to availability of different chemotherapeutic agents. This study presents clinical, haematological and immunophenotypic profile of patients with HCL seen over a period of four years in a tertiary care hospital in north India. Methods: Twenty one cases of hairy cell leukaemia were analyzed for their clinical details, haemogram, bone marrow examination and immunophenotypic findings. Results: Age of the patients ranged from 28-76 yr with male predominance. Weakness and fever were commonest presentations. Splenomegaly, hepatomegaly, lymphadenopathy were seen in decreasing order of frequency. Anaemia was noted in all 21 patients, leukopenia in 15 and thrombocytopenia in 19 cases. Fourteen patients were pancytopenic. Bone marrow examination showed typical hairy cells in all cases. Immunophenotyping showed expression of CD19, CD20, CD103, CD25 and CD11c in all cases, while positivity was seen for CD79b in 93.7 per cent, kappa light chain restriction in 60 per cent and lambda in 40 per cent cases. Notably, 20 per cent showed CD10 and 12 per cent showed CD23 expression. Interpretation & conclusions: This study reveals some unusual findings in otherwise classical disease entity, like absence of palpable spleen, presence of lymphadenopathy, normal or elevated leukocyte counts, expression of CD10, which at times could be diagnostically challenging.