Solitary nonepidermotropic T cell pseudolymphoma of the skin.

A possibly new type of T cell pseudolymphoma is described in three cases. It presented as a small, solitary lesion on the trunk of 3 to 5 months' duration. It was slightly elevated, round, and erythematous, with a diameter of 1 to 2 cm. It showed a tendency to regress spontaneously. In sharp contrast to its benign clinical appearance and biologic behavior, a distinct malignant histopathologic picture was observed, however. It was characterized by a nonepidermotropic bandlike subepidermal infiltrate dominated by large T lymphocytes with cerebriform nuclei identical in morphologic and immunologic characteristics to the abnormal cellular component of cutaneous T-cell lymphomas.