A 23-year-old man with classic Hodgkin lymphoma (cHL) involving multiple lymph nodes, stage IIIB, International Prognostic Score 5, was treated with adriamycin, bleomycin, vinblastine, and dacarbazine, with a partial response. By the end of chemotherapy, his B symptoms resolved, but he had a new inguinal rash with pruritus. A computed tomography scan revealed bilateral inguinal bulky lymphadenopathy. A punch biopsy showed fragments of skin with multiple foci of lymphoid infiltrate (panel A; original magnification ×40, hematoxylin and eosin [H&E] stain) composed of numerous Reed-Sternberg and Hodgkin-like cells on a background of small lymphocytes and eosinophils (panel B; original magnification ×200; inset, original magnification ×1000; H&E stain). Immunohistochemical stains showed that the large neoplastic cells are positive for PAX5 (dim) (panel C; original magnification ×400), CD3 (focally) (panel D; original magnification ×1000), and CD15 and CD30 (panel E; original magnification ×40; inset, original magnification ×1000) and negative for CD2, CD4, CD5, CD7, CD8, CD20, CD45, and ALK-1. In situ hybridization for Epstein-Barr virus was negative. These histologic and immunophenotypic findings support the diagnosis of recurrent cHL.

This interesting case demonstrates skin involvement by cHL with CD3 expression. Because cHL has a 0.5% to 3% chance of involving skin and a 5% chance of expressing T cell markers, it is extremely rare to see both of these events in the same patient.