A case of systemic anaplastic large cell lymphoma with 'Hodgkin-like' appearance and skin involvement mimicking lymphomatoid papulosis.

We report a unique case of the CD30+ anaplastic large cell lymphoma (ALCL). A 44-year-old Japanese male presented with lymphadenopathy followed by skin involvement. Initially, a swollen cervical lymph node was recognized in 1989 and relapsed in 1991, which was histologically diagnosed as Hodgkin disease of nodular sclerotic type. In 1996, he presented ulcerative cutaneous nodules and swollen lymph nodes in his left inguinal region, which was then diagnosed with CD30+ ALCL. Both the lymphadenopathy and the skin lesion had been completely remitted by combining chemotherapy followed by radiotherapy. Thereafter, he had relapsing and remitting episodes of multiple papules and nodules on his face, trunk and extremities for 10 years. Repeated histopathological examination revealed similar tumor cell proliferation in the papules/nodules of the skin. Essentially similar immunohistochemical features, including CD30 and granzyme B expression, but not anaplastic lymphoma kinase (ALK), strongly suggested that all these tumors were sequential expression of one disease continued for 19 years. This case was finally diagnosed as CD30+ ALCL with unique skin involvement mimicking lymphomatoid papulosis (LyP).