Solitary primary cutaneous CD30+ large cell lymphoma of natural killer cell phenotype bearing the t(2;5)(p23;q35) translocation and presenting in a child.

Primary cutaneous CD30+ large cell lymphoma is an unusual tumor most commonly seen in adults. Most of these lymphomas are of T-cell origin and carry a good prognosis. We present the case of a 4-year-old girl with stage IEA CD30+ large cell lymphoma with a CD56+ natural killer cell phenotype and the t(2;5)(p23;q35) translocation. After excision, the patient has been free of disease for 44 months. Primary cutaneous CD30+ large cell lymphoma is uncommon in children. To our knowledge, primary cutaneous CD30+ natural killer type lymphoma has not been reported previously. The indolent behavior of this tumor indicates its similarity to other primary cutaneous CD30+ large cell lymphomas and its difference from other CD56+ lymphomas involving the skin, which often exhibit an aggressive clinical course. Cases such as this one illustrate why the use of a single, or even a few, immunohistochemical stains can be misleading in regard to lymphoma classification and prognostication.