This report describes the clinical and pathological features of cutaneous lesions observed in a 73-year-old woman with terminal adult T-cell leukemia/lymphoma (ATLL) and a 42-year-old man who had chronic ATLL with persistent nasal stuffiness and rhinorrhea of 2 years' duration. Histology of the skin lesions from these two cases showed large blood vessel (arterial and venous) involvement at the level of the dermosubcutaneous junction, in which angiocentric and angiodestructive infiltration of the tumor cells was prominent and reminiscent of lymphomatoid granulomatosis (LYG) and/or polymorphic reticulosis. ATLL commonly involves the skin. Moreover, it may originate in the skin. The majority of researchers have observed perivascular and periadnexal infiltration, frequent epidermal exocytosis with Pautrier's microabscesses, and the occasional presence of leukemic cells within the vascular lumen; however, vascular involvement like that seen in our cases has not been described before. Our cases suggest that a variety of T-cell malignancies may be angiocentric and angiodestructive in nature, and that so-called LYG and LYG-like malignant lymphomas are not a single disease, but may constitute a heterogeneous group of T-cell malignancies including ATLL.