Mammography in the evaluation of nipple inversion

The purpose of this study was to correlate the clinical and mammographic appearances of the nipple, determine the effects of breast compression on nipple position, and describe the mammographic findings in women with nipple inversion.

We examined 312 consecutive women who were referred for mammography using routine craniocaudal and mediolateral oblique views, which resulted in 595 breasts imaged Nipple position (normal or inverted) was assessed visually, both with and without breast compression, and correlated with the findings at mammography.

Of the 312 women, 29 (9%) had visually inverted nipples without breast compression; similarly, of the 595 breasts, 36 (6%) had visually inverted nipples without breast compression. Clinical nipple inversion was chronic in 33 (92%) of 36 breasts and acute in the remaining three breasts (8%) Nipple inversion occurred at birth in one (3%) of 36 breasts, during puberty in 21 (58%), and during adulthood in 14 (39%). Reported causative factors were pregnancy in one (3%) of 36 breasts, nursing in one (3%), prior benign biopsy in one (3%), and prior cancer in one (3%). In the other 32 breasts (89%), causative factors were not known. Both visually and mammographically, 29 (81%) of 36 clinically inverted nipples remained inverted with breast compression, but seven (19%) became normal in position. Of the 312 women, 23 (7%) had inverted nipples on mammography; likewise, of the 595 breasts, 29 nipples (5%) were inverted on mammography. Mammographic findings in the 33 breasts with chronically inverted nipples were normal in 29 (88%), probably benign masses in two (6%), multiple cysts in one (3%), and axillary lymphadenopathy in one (3%). Mammographic findings in the three breasts with acutely inverted nipples were normal in two (67%) and revealed a suspicious mass in one (33%).

Mammography often failed to reveal nipple inversion; nearly one in five clinically inverted nipples became normal in position as a result of breast compression. In the vast majority of women with nipple inversion, the process was long-standing and without causative factors. Also, these women typically lacked mammographic findings suggestive of malignancy. Of the 14 patients with nipple inversion that had occurred during adulthood, two women (14%) had an underlying malignancy.