Rosai-Dorfman disease of the subglottis diagnosed by ultrasound-guided fine-needle aspiration biopsy: a case report.

We report a case of subglottic narrowing caused by an extranodal deposit of sinus histiocytosis in a 55-year-old man. To the best of our knowledge, no previous reports have described diagnosis using sonographic-guided fine-needle aspiration cytology for Rosai-Dorfman disease of the subglottis. This patient was diagnosed by sonographic-guided fine-needle aspiration biopsy, which revealed lymphocytes, plasma cells, and many foamy, multinuclear histiocytes with preserved lymphocytes in their cytoplasm (emperipolesis). The patient underwent an incisional biopsy of the tumor and received postoperative steroids and low-dose chemotherapy. The subglottic tumor was markedly regressed 6 months later.