Primary cutaneous CD30-positive large cell lymphoma: definition of a new type of cutaneous lymphoma with a favorable prognosis. A European Multicenter Study of 47 patients.

Background: CD30 (Ki-1)-positive anaplastic large cell lymphoma (LCL) has been described as a morphologically distinct group of LCL that generally are associated with a poor prognosis. Recent studies indicate that these lymphomas, when confined to the skin, have a favorable prognosis. However, there is no consensus regarding the definition of these primary cutaneous CD30-positive LCL. Reported patients have been selected variously on the basis of morphologic (anaplastic cytology) or immunophenotypical (expression of CD30 antigen) criteria.

Methods: At two recent workshops aimed to achieve consensus on the definition and terminology of these lymphomas, the clinical, histologic, and immunophenotypical data of 47 patients with primary cutaneous CD30-positive LCL from five collaborating European centers were analyzed.

Results: Characteristic clinical features were presentation with solitary or localized skin lesions (42 of 47 patients), frequent cutaneous relapses (15 patients), and partial or complete spontaneous remission of skin lesions (11 patients). Twelve of 47 (25%) patients developed extracutaneous disease. The favorable prognosis of these lymphomas is indicated by the follow-up data that show that 36 of 47 patients are alive and in complete remission, only four disease-related deaths have occurred, and the overall median survival is 42 months (range, 2-130 months). There were no differences in clinical presentation, course, or prognosis between anaplastic and nonanaplastic CD30-positive LCL.

Conclusion: The results of this study indicate that primary cutaneous CD30-positive LCL, regardless of their morphologic classification (anaplastic or nonanaplastic) can be considered as a distinct type of cutaneous T-cell lymphoma. Recognition of this type of cutaneous lymphoma is important because it may prevent patients from unnecessary aggressive treatment.