Primary cutaneous extranodal natural killer/T-cell lymphoma presenting as bilateral erythematous patches on the arms.

Natural killer/T-cell lymphoma is a rare, Epstein-Barr virus-associated type of cytotoxic lymphoma thatpresents mainly in the nasal cavity and its vicinity. Very few cases of primary cutaneous extranodal natural killer/T-cell lymphoma have been reported till date. All the previously reported cases of primary cutaneous extranodalnatural killer/T-cell lymphoma presented as lesions resembling cellulitis, subcutaneous nodules or ulcers. We report a rare case which presented as erythematous and purpuric round patches on the arms and was finally diagnosed as primary cutaneous extranodalnatural killer/T-cell lymphoma, following a skin biopsy. The atypical patchy lesions presented a diagnostic challenge. We herein describe this clinically novel atypical patch-like presentation of primary cutaneous extranodalnatural killer/T-cell lymphoma together with the key histopathologic features and highlights of the previously reported cases.