Unusual Presentation of Marginal Zone Lymphoma

Primary cutaneous B-cell lymphomas (pcBCLs) are non-Hodgkin lymphomas that present with exclusive cutaneous disease at the time of diagnosis. The lesions may be indolent, subtle, or waxing and waning, making the diagnosis challenging. The ear is an uncommon location, and its frequency of involvement remains unknown. A retrospective analysis of a single patient with primary cutaneous marginal zone lymphoma of the ear. The patient was a 44-year-old male who presented with erythematous tender nodules on the left superior posterior helix. Shave biopsy revealed mixed dermal lymphoid infiltrate with eosinophils and telangiectasias. The patient was diagnosed with angiolymphoid hyperplasia with eosinophilia. Multiple treatment regiments were trialed but failed due to lack of therapeutic response, relapse, and clinical progression. The patient ultimately underwent Mohs surgery with biopsy findings that demonstrated CD-20 positive cells. Evaluation with B-cell histopathology and gene rearrangement studies confirmed the diagnosis of marginal zone lymphoma. This case report shows a unique presentation of marginal zone lymphoma of the ear, initially diagnosed as angiolymphoid hyperplasia with eosinophilia. Our findings demonstrate a relatively rare presentation for this disease and highlight the challenges in diagnosing primary cutaneous marginal zone lymphoma.