A rare and isolated presentation of primary cutaneous anaplastic large cell lymphoma.

Primary cutaneous anaplastic large cell lymphoma is a CD30+ lymphoproliferative disorder of the skin characterized by the absence of nodal and visceral involvement, low recurrence rate, spontaneous remission, and tendency to occur in patients older than 20 years. The case presented here is of a 15-year-old boy with grouped papular lesions arranged in an annular fashion with a central clearing on his right arm for 4 months that was diagnosed with a case of anaplastic lymphoma kinase-negative primary cutaneous CD30+ anaplastic large cell lymphoma. The CT scan, bone marrow biopsy, and laboratory data ruled out systemic involvement. He was treated with oral methotrexate 10 mg once a week, but was lost to follow-up.