Mediastinal follicular dendritic cell sarcoma with paraneoplastic pemphigus.

Follicular dendritic cell sarcoma is a rare neoplasm of immune accessory cells. It occurs primarily in lymph nodes. Occurrences in the mediastinum are rarely reported. Diagnosis and management of follicular dendritic cell sarcoma remain unclear, and it is an under-recognized clinical entity. Only a few cases of paraneoplastic pemphigus as the first presentation of follicular dendritic cell sarcoma have been reported. We report an unusual case of follicular dendritic cell sarcoma of the anterior mediastinum, presenting as paraneoplastic pemphigus in a 62-year-old man. Typical histological features confirmed the diagnosis of follicular dendritic cell sarcoma, and surgical resection was successfully performed.