Nipple Adenoma: Case Report of a Rare Entity

Abstract

A nipple adenoma is a rare benign breast tumor. The commonest presentation of this rare entity is nipple erosion, serosanguinous discharge, induration, or tumor formation at the nipple. It often mimics malignant breast lesions or nipple eczema and is mistaken for Paget's disease of the nipple or dermatological pathology. It may be misdiagnosed pathologically as ductal carcinoma of the breast. This may cause a diagnostic delay or a faulty diagnosis. Treatment is the excision of the tumor with or without nipple excision. Here, we report a case of nipple adenoma that projected out of the nipple along with nipple erosion, serosanguinous discharge, and occasional bleeding from the adenoma. A 37- year-old woman presented with a tumor on her right nipple for eight months, with the erosion of the nipple and serosanguinous discharge. The patient gave a history of a small amount of bleeding occasionally. Axilla was normal. The patient was advised to have a mammosonography. It showed an oval-shaped, well-demarcated, hypoechoic, uniformly solid nodule in the right nipple. There was no microcalcification seen on mammography. A punch biopsy was done to establish the diagnosis. It showed ductal hyperplasia and papillary proliferation of glandular structures suggestive of nipple adenoma. Complete resection of the tumor with partial excision of the nipple was done with a satisfactory cosmetic result. Though very uncommon, the possibility of nipple adenoma should be thought of when a patient presents with nipple erosion and discharge with or without a clinically obvious tumor. Timely diagnosis with histopathological correlation is important since it allows for less invasive surgical methods. In our case, we could attain a cosmetically satisfactory outcome without a remnant tumor. Paget's disease of the nipple also has a similar clinical presentation, and it is a premalignant condition. The objective of presenting this case is to highlight the possibility of this rare benign condition, which may be easily missed clinically and also demands careful histopathological examination for its correct diagnosis.

Keywords: erosion; lactiferous duct; myoepithelial cells; nipple adenoma; paget’s disease.

Figure 1. Right nipple adenoma seen projecting out of the nipple. Nipple erosion is evident. Tumor is bright red in color with granulation-like texture.

Figure 2. Oval shaped, well demarcated, uniformly solid nodule without microcalcification on mammography.

Figure 3. (a) Ductal hyperplasia and papillary proliferation of glandular stroma and (b) intact myoepithelium on p63 staining.

Figure 4. (a) Excised tumor. Black arrow indicates tumor part at nipple base. White arrow indicates distal most protruding part of tumor. (b) Tenth postoperative day of reconstructed nipple indicated.