Hepatosplenic T-cell lymphoma diagnosed using flow cytometry. A single-center study of 12 cases from North India

Hepatosplenic T-cell lymphoma (HSTCL) is a rare fatal T-cell neoplasm with unique clinical and laboratory features. There is, however, significant morphological and immunophenotypic heterogeneity which may lead to diagnostic dilemma.

The study was aimed to study the prevalence and clinic-pathological spectrum of this rare variant of T cell lymphoma in the Indian subcontinent.

A retrospective analysis of all consecutive cases of HSTCL diagnosed over a period of 6 years was carried out. The clinical and laboratory parameters of all these patient were reviewed and analysed.

A total of 12 cases of HSTCL were diagnosed during this period which accounted for 1.76% of all non-Hodgkin's lymphomas (NHLs) and 9.1% of all T-cell NHLs. The median (range) age of presentation was 23 (16-30) years.Leukocytosis, peripheral blood (PB) involvement, and a blastic morphology were noted in 41%, 67%, and 58% of the cases, respectively. FCI proved these cells to have a mature, dual-negative (CD4-/CD8-) T-cell phenotype with a gamma-delta T-cell receptor restriction. Frequent loss of CD5 expression (84%) was also noted. These patients invariably had a fatal outcome and majority died within a year of diagnosis.

The incidence of leukocytosis and a blastoid morphology is quite frequent in HSTCL. Hence, a differential diagnosis of HSTCL should always be considered in young patients presenting with splenomegaly and exhibiting atypical lymphoid/blastoid cells in the PB or a marrow. An FCI can readily diagnose and differentiate them from an acute lymphoblastic leukemia/lymphoma.