A bloody nipple discharge can be brownish in appearance and reflect an underlying carcinoma. An intraductal papilloma is the cause of most cases of spontaneous single duct nipple discharge. A ductogram may localize the lesion but cannot differentiate between benign and malignant lesions. Cytology of the nipple discharge is rarely useful. A definitive histologic diagnosis can only be made on sections of the surgically excised specimen. Gynecologic Oncology, Morrow et al, 1993. TF