HTLV-1 is a virus that is endemic in southwesternJapan and the Caribbean and has been implicatedin the development of ATLL. ATLL, which is anuncommon malignant condition of peripheralT-lymphocytes, is characterized by four clinicalsubtypes, which include acute, lymphomatous,chronic, and smoldering types, that are based onLDH levels, calcium levels, and extent of organinvolvement. We present a 52-year- old woman withpruritic patches with scale on the buttocks and withtender, hyperpigmented macules and papules oftwo-years duration. Histopathologic examinationwas suggestive of mycosis fungoides, laboratoryresults showed HTLV-I and II, and the patient wasdiagnosed with primary cutaneous ATLL. We reviewthe literature on HTLV-1 and ATLL and specifically theprognosis of cutaneous ATLL. The literature suggeststhat a diagnosis of ATLL should be considered amongpatients of Caribbean origin or other endemicareas with skin lesions that suggest a cutaneousT-cell lymphoma, with clinicopathologic features ofmycosis fungoides. Differentiation between ATLLand cutaneous T-cell lymphoma is imperative as theyhave different prognoses and treatment approaches.