Characterization of the spectrum of postthymic T-cell malignancies in Taiwan a clinicopathologic study of HTLV-1-positive and HTLV-1-negative cases

Abstract

Postthymic T‐cell malignancy shows marked geographic, clinicopathologic, and prognostic diversity. The frequency and spectrum of T‐cell malignancies in Taiwan were investigated. Fifty‐two patients (35 male and 17 female) with a median age of 49 years, were consecutively encountered between October 1983 and April 1987; these accounted for 39% of non‐Hodgkin's lymphoma cases seen in our institutions. Ten patients (19.3%) had adult T‐cell leukemia/lymphoma (ATL) associated with human T‐cell leukemia virus (HTLV‐1). Patients with ATL had disease similar to that reported from southwestern Japan and the Caribbean. They had frequent skin lesions (60%), hypercalcemia (40%), and a rapid clinical course with a median survival of 1.3 years. The 35 HTLV‐1‐negative peripheral T‐cell lymphomas (PTL) were similar to PTL in western countries, manifesting frequent visceral, cutaneous, and vascular tropisms. Marrow involvement was documented at presentation in 39% and Stage III/IV disease in 80% of the PTL patients. The histology of PTL usually expressed prominent reactive features which is distinct from that in ATL. Several subcategories could be defined: Hodgkin's‐like PTL in nine patients, T‐zone lymphoma in three, angioimmunoblastic lymphadenopathy‐like lymphoma in one, Lennert's lymphoma in three, and angioinvasive lymphoma in four. Two HTLV‐1‐negative PTL had neoplasiic cells with clover‐shaped nuclei and were designated as ATL‐like. Morphologic classification based on the modified Working Formulation showed prognostic correlation, with median survival of less than 6 months for large cell/immunoblastic PTL, compared with 5 years for patients with small/medium cell PTL. Both low‐ and high‐grade PTL seem to represent an incurable disease. Classical cutaneous T‐cell lymphoma (seven cases) is relatively unusual in Taiwan, compared with the frequency of PTL. Post‐thymic T‐cell malignancies in Taiwan include HTLV‐1‐positive and HTLV‐1‐negative diseases, both of which have a poor prognosis and resemble similar T‐cell malignancies in the East and West.