HTLV-1-associated cutaneous disease: a clinicopathological and molecular study of patients from the U.K

The clinicopathological features of eight patients with cutaneous disease associated with HTLV-1 infection are reviewed. All were U.K. residents of West Indian extraction, and two are currently alive. Disease remained confined to the skin in two patients. Five patients with a cutaneous prodromal phase developed leukaemia after a median duration of 124 months (3 months-21 years), and in one of these combination chemotherapy produced a sustained clinical remission for 20 months. Two patients developed cutaneous disease after remission of their leukaemia. Cutaneous lesions were heterogeneous and included localized papules, a generalized papulonodular eruption, diffuse and localized erythematous plaques, pompholyx-like lesions on the palms and soles, and tumours. The histology of the skin lesions was also variable, and consisted of a heavy dermal infiltrate with lymphocytes, histiocytes, plasma cells, eosinophils and cytologically atypical mononuclear cells. Epidermotropism was present in biopsies from five patients. Tumour cells with large, densely staining, pleomorphic nuclei, arranged in rows between collagen bundles, were present in the majority of cases. In one patient the infiltrate also consisted of epithelioid cells and multinucleated giant cells. Six cases were classified histologically as pleomorphic T-cell lymphoma, and two as cerebriform or mycosis fungoides type. Molecular studies revealed a clonal T-cell population associated with monoclonal integration of HTLV-1 provirus in tissue DNA from six patients. In two patients HTLV-1 integration was established retrospectively using enzymatic in vitro amplification of a specific HTLV-1 po1 gene sequence in DNA extracted from paraffin-embedded sections. This study indicates that the clinical and pathological features of HTLV-1-associated cutaneous disease are diverse. Patients may have disease confined to the skin for prolonged periods, either at presentation or following clinical relapse--cutaneous adult T-cell lymphoma. Molecular techniques allow distinction from other types of cutaneous T-cell lymphoma, and provide an opportunity for retrospective studies of archival material.