Diagnosis of hairy cell leukaemia by fine needle aspiration cytology of lymph node.

Abstract

Hairy cell leukaemia (HCL) is a rare lymphoproliferative disorder of B cell origin, and uncommonly it affects the lymph node. Fine needle aspiration cytology (FNAC) of lymph node of HCL has rarely been described. A 41-year-old man presented with pallor, fever, tachycardia, generalized lymphadenopathy, and massive splenomegaly. The FNAC of the cervical lymph node was done. The smears showed many atypical lymphocytes with a plasmacytoid appearance. There were many large cells with round to reniform shaped nuclei having with hair-like cytoplasmic processes. Flow cytometry (FCM) revealed a clonal B cell population with light chain restriction and positive CD20, CD79b, CD22, CD11c, CD25, CD103, CD123, and CD200 markers. The characteristic cytological features such as atypical lymphoid cells, large cells with hairy projections along with FCM findings, are helpful in the diagnosis of HCL.