BREAST MR AND THE APPEARANCE OF THE NORMAL AND ABNORMAL NIPPLE

Aim: To identify the magnetic resonance (MR) morphological and enhance ment characteristics of the normal and diseased nipple, Materials and methods: The MR appearances of the nipple in 35 patients with known pr imary breast cancer who went on to mastectomy was reviewed by two radi ologists (blinded to the clinical? mammographic and histopathological information) and correlated with histology. The appearance of the cont ra-lateral nipple in 31 patients was reviewed and compared with that o f the affected side, MR was performed at 1.0T using a receive-only dou ble breast coil in 33 patients and a single breast coil in two patient s, Three dimensional (3-D) T1-weighted gradient-echo images were made before and immediately after a fast hand injection of gadolinium-DTPA (0.1 mmol/kg). Results: Twenty-six breasts had histopathologically nor mal nipples and retroareolar tissue, four had evidence of tumour withi n the nipple and four had retroareolar tumour but with nipple sparing, Fifteen normal nipples were everted and II were inverted (flat), All showed superficial linear dermal enhancement above a non-enhancing zon e in the nipple areolar complex. Linear or patchy enhancement deep to the non-enhancing zone was seen in four breasts and linear enhancement through the non-enhancing zone was seen in tno, The nipple in all fou r breasts with tumour involvement showed increased thickening/bulkines s and enhancement of the nipple-areolar complex and retroareolar tissu e, The four breasts with retroareolar tumour and nipple sparing showed increased thickening and enhancement of the retroareolar tissue only, There was one false positive result on breast MR for retroareolar tum our involvement. In this case the abnormally enhancing retroareolar ti ssue adjacent to the focal mass was shown to be an area of sclerosing adenosis on histology. The 31 contra-lateral nipples had the character istic 'normal' appearance and when compared with its normal ipsilatera l nipple showed marked symmetry, When compared with its abnormal ipsil ateral nipple showed marked asymmetry, Conclusion: MR of the breast ca n show nipple involvement even when clinically unsuspected, This is im portant for treatment planning of breast cancer, in particular nipple preserving surgery.