Primary cutaneous large B-cell lymphoma of atypical presentation: case report.

Primary cutaneous lymphomas are defined as lymphocytic neoplasias that present themselves clinically in the skin without extracutaneous disease at diagnosis and up to 6 months after it. The authors report the case of an elderly male patient, with a three- month-history of papules in the axilla which evolved into painful ulceration. Examination found deep ulcer with irregular borders ,infiltrates, in the right axilla. Physical and additional examinations did not evidence disease at distance. Histopathology revealed dense and diffuse dermic sample infiltrate of atypical lymphocytes. Imunohistochemistry shows expression of CD20 and bcl-2 antigens , with negative CD10, configuring diagnosis of cutaneous large B-cell lymphoma. In this type of cutaneous lymphoma, primary cutaneous manifestation is rare ,the incidence in men is lower and it is most commonly located in the lower limbs.