Retroperitoneal ganglioneuroma: a report of diagnosis by fine-needle aspiration cytology.

Ganglioneuroma is a rare benign tumor composed of nerve fibers and mature ganglion cells. Because it shares morphologic features with other neural tumors, both benign and malignant, accurate preoperative diagnosis is often difficult, but nonetheless, critical for proper management. The use of fine-needle aspiration (FNA) cytology in the diagnosis of ganglioneuroma has been rarely documented. In this report, a 25-yr-old man presented with a large retroperitoneal ganglioneuroma that was initially diagnosed by FNA cytology. This case illustrates the utility of FNA cytology in the diagnosis of ganglioneuroma and supports the routine incorporation of FNA cytology in the evaluation of retroperitoneal masses.