Primary cutaneous CD30-positive anaplastic large cell lymphoma in childhood: report of 4 cases and review of the literature.

We present the clinicopathologic findings in 4 children with primary cutaneous anaplastic large cell lymphoma (C-ALCL). The patients ranged in age from 13 months to 8 years, with 3 females and 1 male. All presented with a rapidly enlarging mass involving the skin and subcutaneous tissue. Histologic evaluation showed sheets of large pleomorphic lymphoid cells that were diffusely and strongly CD30(+). Tumor cells were CD45(+) in 1 of 4 cases. Cells were of T-cell phenotype, with variable positivity for CD3 (3 of 4 cases) and CD5 (2 of 4 cases). All 4 cases were positive for CD4 and clusterin. Staining for anaplastic lymphoma kinase was negative in all cases. No evidence of systemic involvement was noted at initial presentation or over a follow-up of 5 to 78 months, although 3 patients had cutaneous recurrences. Primary C-ALCL has only rarely been described in the pediatric population. The high-grade histologic appearance of this lymphoma belies its generally favorable clinical course and prognosis. Recognition of this entity and its differentiation from other T-cell lymphomas that secondarily involve the skin is important to avoid unnecessarily aggressive therapy in these children.