Systemic B-cell lymphoma presenting as an isolated lesion on the ear

We report a case of systemic B-cell lymphoma that presented as an isolated cutaneous lesion on the ear, mimicking a primary cutaneous B-cell lymphoma, Although there was no clinical evidence of systemic disease, bone marrow i nvolvement was found on further investigation and subsequent immunoglobulin gene analysis revealed an identical clone in the skin lesion and bone marr ow aspirate. Evidence of a t(14 : 18) translocation was not identified. Thi s case is unusual for several reasons, First, involvement of the pinna as a presenting feature of systemic lymphoma has not been reported previously. Second. the cutaneous lesion had been present for 3 years prior to diagnosi s and there has been no clinical progression of systemic lymphoma during 2 years of follow-up. Third, the lymphoma does not correspond exactly to any of the entities in the REAL classification of systemic B-cell lymphoma. Thi s case underlines the indolent nature of some systemic B-cell lymphomas and the need to investigate thoroughly patients with disease apparently confin ed to the skin.