We present a rare case of
adult T cell leukemia/lymphoma (ATL) in which leukemic T cells expressed CD4 and CD25
surface antigens and infiltrated mammary glands during
clinical course of the disease. A 40-year-old male was admitted with long-standing skin lesions and
leukocytosis. Peripheral blood lymphocytes were highly pleomorphic and presented CD2, CD4, CD25, CD38 membrane
surface antigens. The patient proved to be seropositive for human T-cell lymphotropic virus type I (
HTLV-I) antibodies. Monoclonal expansion of lymphoid cells integrated with HTLV-I genome was observed, and the diagnosis of ATL chronic type was made. He underwent a
chemotherapy regimen, and skin lesions and
leukocytosis improved markedly. He progressed with an indolent
clinical course of ATL, when he was admitted with bilateral
hyperplasia of breast, recurrent skin lesions, and
leukocytosis. Breast biopsy revealed bilateral gynecomasty, extensive
leukemic infiltration of typical ATL cells in the mammary glands, and the presence of mammary epithelial cells productively infected with HTLV-I. This is the first report describing invasion of the mammary tissue with HTLV-I-transformed T-cells and HTLV-I-associated
breast disease.