Lymphoma- and leukemia-associated cutaneous atypical CD30+ T-cell reactions.

Cutaneous CD30+ lymphoid infiltrates appear cytologically atypical and occasionally may be misinterpreted as recurrent disease when they occur in patients treated for other primary hematologic malignancies. We recently encountered two such cases and present our findings. One patient with B-cell lymphoma and another with myeloid leukemia developed cutaneous eruptions after chemotherapy displaying highly atypical perivascular lymphoid cells on histology that mimicked recurrent disease. In both cases, the lymphocytes were CD30+ T cells by immunohistochemistry. The skin lesions spontaneously resolved and have not recurred. Because one case was initially misinterpreted as recurrent leukemia, we conclude that close clinical correlation and immunophenotypic confirmation should be done for atypical cutaneous lymphoid infiltrates in patients with primary hematologic malignancies. We discuss the differential diagnosis of atypical CD30+ infiltrates in this setting, which include recurrent lymphoma or myeloid leukemia, primary cutaneous anaplastic large cell lymphoma (ALCL), lymphomatoid papulosis (LyP), carbamazepine-induced CD30+ pseudolymphoma, viral infection and an atypical eruption of lymphocyte recovery.