A case of cutaneous involvement of T-cell lymphoblastic lymphoma

Lymphoblastic lymphoma is a malignant neoplasm of precursor lymphocytes with a B- or T cell phenotype. T cell lymphoblastic lymphoma is a clinically aggressive disease with frequent involvement of extranodal sites, but the involvement of the skin is rare. The clinical appearance of skin lesions usually includes single or multiple papular or nodular lesions preferentially located on the head and neck. Herein, we report the case of a 31-year-old man presenting with skin involvement of T cell lymphoblastic lymphoma. The lesions manifested as asymptomatic, multiple, round, reddish brown macules, and patches on both extremities. Histology examination showed dense, diffuse infiltration of medium sized lymphoid cells into the entire dermis. The tumor cells had irregular nuclei, finely dispersed chromatin, inconspicuous nucleoli, scant cytoplasm, and expressed TdT, CD3 and CD5.