Clinico-pathological profile of Hairy cell leukemia: Critical insights gained at a tertiary care cancer hospital.

Context: Hairy cell leukemia (HCL) is a rare, low grade, B-cell neoplasm with a characteristic morphologic and immunophenotypic profile. It has to be distinguished from chronic lymphoproliferative disorders because of different treatment protocol and clinical course. Aims: To evaluate clinicopathological features including immunophenotypic analysis of cases diagnosed as HCL. Materials and Methods: The present study included 28 cases diagnosed over a period of nine years (2002-2010). Clinical presentation, complete blood count, bone marrow aspirate, and flow cytometric analysis of cases were reviewed. Treatment and follow-up details (ranging from 3-90 months) were noted. Results: This study revealed 28 cases (referrals-7, indoor-21), aged 26-69 years with a median age of 47 years, with a male predominance (M:F=6:1). The presenting complaints were weakness (80%) followed by fever (56%) and abdominal pain. Physical examination revealed splenomegaly in most patients (92%) and hepatomegaly in a minority (28%). The common laboratory features were anemia in 23 cases, pancytopenia in 14 cases, while two patients had leukocytosis and three patients had normal WBC count. Dry tap was observed in 84% of the cases where hairy cells constituted 16-97% of non-erythroid nucleated cells. Tartarte resistant acid phosphate staining was positive in all the eight cases where it was done. CD5 was negative in all the cases, while CD10 was expressed in three cases (13%) and CD23 in five cases (19%). Conclusions: Though pancytopenia is common, occasional patient can present with normal blood counts or leukocytosis. Few unusual findings include presence of lymphadenopathy, absence of palpable splenomegaly, and expression of CD23 and CD10 by the leukemic cells.

Parvovirus B19 presenting with persistent pancytopenia in a patient of T-ALL post induction chemotherapy diagnosed on bone marrow examination.

Manifestations of parvovirus B19 vary even in the normal host from asymptomatic or subclinical infection to a spectrum of illness with symptoms during viremic and immune complex mediated stage of disease. We report the morphological findings of parvovirus B19 infection (confirmed on serology) in a patient of T-acute lymphoblastic lymphoma (T-ALL) who underwent induction phase of chemotherapy (MCP 842 protocol). Persistent pancytopenia in the bone marrow aspirate with mild increase in blasts was thought to be due to failure to achieve marrow remission. However, giant pronormoblasts with prominent intranuclear inclusions confirmed on trephine biopsy led to the suspicion of parvovirus B19 infection which was later confirmed on serology. This case is presented to report the rarely seen classical morphological feature of parvovirus infection on bone marrow examination which was incidentally the first investigation to diagnose the viremic phase of the infection, indicating that a high index of suspicion needs to be kept in mind while examining bone marrows of susceptible patients.

Leukemic phase of anaplastic lymphoma kinase positive, anaplastic large cell lymphoma.

Anaplastic large cell lymphoma (ALCL) is a distinct type of CD30+ T/null-cell non-Hodgkin's lymphoma that frequently involves nodal and extranodal sites. The presence of leukemic phase in ALCL is extremely rare and occurs exclusively with ALK1-positive ALCL. We describe two patients with ALK1-positive ALCL who developed a leukemic phase with rapid progression of the disease. Immunophenotypic pattern assessed on peripheral blood by flow cytometry revealed CD45, CD30, and CD25 positivity in both cases but NPM-ALK1 was expressed in only one case. Both patients developed leukemic phase as a terminal event of the disease and we share the immunophenotypic features of both cases.