Node-based T cell lymphoma. The clinical, immunological and morphological spectrum.

Four cases of node-based T cell lymphoma are presented. The tumours had 2 distinct morphologic patterns. Two cases showed a polymorphous proliferation of pleomorphic lymphoid cells, small lymphocytes, epithelioid cells and arborizing small vessels while the others displayed a monomorphous infiltrate of large atypical lymphoid cells characterized by granular nuclei with numerous tortuous folds to produce a 'squiggly' appearance. One case showed a progression from one histological pattern to the other. Confirmation of the T cell nature of these lymphomas was based on the demonstration of E-rosette formation by morphologically atypical lymphoid cells which also stained positive for acid alpha-naphthyl acetate esterase activity. The patients had an average age of 52 yr and presented with a variable distribution of lymphadenopathy and a predominance of extranodal involvement. Two cases disclosed hypergammaglobulinaemia, one of whom had a paraproteinaemia of IgM-k type. All patients responded poorly to standard combination chemotherapy, 2 expiring 48 and 53 mth after onset of symptoms.