Malignant Lymphoma, T-cell Type: A Distinct Morphologic Variant with Large Multilobated Nuclei, with a Report of Four Cases

Abstract

Clinical, morphologic, and immunologic features in four cases of a cytologically distinctive variant of T-cell lymphoma of large multilobated lymphoid (“histiocytic”) cell type are described. Clinical features included weight loss, fever, and night sweats. The ages of the patients ranged from 42 to 63 years. An extranodal manifestation and distribution of disease was observed in three of the four patients, with a predilection for skin and subcutaneous tissue, bone, gonads, and the central nervous system. Lymphadenopathy was present in all cases but represented the major clinical finding in only one. Splenomegaly was not observed. Histologically, the lymphomatous infiltrate was characterized by large lymphoid cells with markedly irregular, multilobated or hypersegmented nuclei, with relatively fine chromatin, and small to inconspicuous nucleoli. Neoplastic lymphoid cells were identified as T-cell type on the basis of spontaneous rosette formation with sheep erythrocytes (E rosettes). Cytochemically, these cells demonstrated strong punctate cytoplasmic acid phosphatase activity, and α-naphtyl butyrate esterase activity (punctate or dot-like staining pattern). The unusual cytologic features of this variant of malignant lymphoma differentiate it from other types of non-Hodgkin’s lymphomas, and from non-lymphoid malignancies, which it may simulate histologically and clinically.