CD30+ lymphoproliferative disorder: primary cutaneous anaplastic large cell lymphoma followed by lymphomatoid papulosis.

CD30+ large anaplastic lymphoid cells are seen in anaplastic large cell lymphoma (ALCL), and also in lymphomatoid papulosis (LyP) and other lymphoproliferative disorders. It can be difficult precisely to categorize these disorders with CD30+ cells. We report a case of primary cutaneous CD30+ ALCL with systemic metastases in whom the clinical disease subsequently evolved into LyP. The patient was initially administered cisplatin and etoposide and made a good response. Eighteen months later, recurrent, self-healing cutaneous small nodules appeared around the original tumour site without any systemic involvement. Histopathological examination of the recurrent lesions revealed infiltration with a mixture of cells that included neutrophils, eosinophils and CD30+ large anaplastic cells cytologically identical with those in the primary lesion. The anaplastic cells in both the primary and recurrent lesions were positive for monoclonal antibodies CD30, CD25 and a monoclonal antibody directed against the chimeric protein p80(NPM-ALK). These observations suggest the possibility that the ALCL and the subsequent LyP represent different clinical manifestations of proliferation of the same clone.