Dermatologic and histologic features of cutaneous gamma-delta T-cell lymphoma.

(A) Characteristic ulcerated tumors covered with hemorrhagic crust. (B) Multiple pink to plum–colored tumors in an upper extremity. (C) Low magnification shows an example of the coexistent epidermotropic, dermal, and subcutaneous patterns of involvement in a single biopsy. Original magnification, × 25. There is psoriasiform epidermal hyperplasia and a bandlike lymphocytic infiltrate in the papillary dermis with epidermotropism. The infiltrate extends into the reticular dermis with a perivascular pattern. In addition, there is infiltration of subcutaneous tissue reminiscent of lobular panniculitis. (D) The dermal infiltrate is positive for TCRδ1 by immunohistochemistry (avidin-biotin complex [ABC] immunoperoxidase; methyl green counter stain). Original magnification, × 100. Adapted from Toro et al,6 and reproduced with permission from Jaffe et al.4