Symmetrical primary cutaneous marginal zone lymphoma associated with rheumatoid arthritis.

Primary cutaneous marginal zone B-cell lymphoma (PCMZL) is an indolent low grade B cell lymphoma of the skin, with lack of extracutaneous involvement at the time of diagnosis. Herein we report the case of a patient with rheumatoid arthritis (RA) who developed symmetrical PCMZL lesions on both ear lobes. Lesions occurring symmetrically on ear lobes are more specific for cutaneous lymphoid hyperplasia (CLH) and this kind of symmetrical localization hasn't been reported for PCMZL before. PCMZL is considered to arise from a background of reactive lymphoid hyperplasia and this case point out the concept of CLH and PCMZL spectrum. Association of marginal zone lymphoma with rheumatoid arthritis and resolution of lesions together with the resolution of symptoms due to rheumatoid arthritis after rituximab therapy is another interesting point for this case. To the best of our knowledge PCMZL associated with RA has not been reported previously.