Bilateral Florid Papillomatosis of the Nipple: An Unusual Indicator for Metachronous Breast Cancer Development—A Case Report

Adenoma or florid papillomatosis of the nipple (FPN) is a rare benign disease which has histopathological features similar to those of a mammary papillary carcinoma. Here, we report a rare case of bilateral florid papillomatosis of the nipple and breast cancer, with a literature review. 1. Introduction Adenoma or florid papillomatosis of the nipple (FPN) is a rare benign disease which clinically resembles Paget’s disease of the nipple and has histopathological features similar to those of a mammary papillary carcinoma [1]. In this report, we discuss a rare case of bilateral florid papillomatosis of the nipple with unilateral breast cancer, followed by a brief literature review. 2. Case Report A 63-year-old Caucasian woman presented to our breast clinic with a cracked right nipple and a chronic yellow discharge for 1 year. She had a left side mastectomy with Latissimus Dorsi flap reconstruction 2 years ago for breast cancer. Histopathological examination of the left mastectomy specimen reported features of left nipple florid papillomatosis along with multifocal ductal carcinoma in situ with apocrine features and microinvasive changes. Twelve years prior to that, she had a benign cyst removed from her left breast. Her mother died of ovarian cancer. Findings on clinical examination were those of eczematous-like changes of her right nipple with crusting and nipple inversion. A yellow discharge could be expressed on examination and no palpable lumps were found in her right breast or either axillae. Her right breast mammogram showed heterogeneous glandular parenchyma which was unchanged compared to previous examinations. No new suspicious mammographic features were identified. The patient has subsequently undergone a major (total) duct excision with a specimen size of ？mm. Histology of the breast tissue included major nipple ducts in the breast tissue, several of which showed florid epithelial hyperplasia with papillary hyperplasia in some areas (Figure 1). Ducts expanded and occluded by solid sheets of cells with focal necrosis were also seen, with periductal fibrosis (Figure 2). Apocrine changes were focally seen (Figure 3). In the first 3 sequential slices, there appeared to be a fairly well-defined nodule suggesting a major duct (or nipple) adenoma. Immunostaining showed strong membranous staining with CK 5/6, indicating preservation of basal/myoepithelial layer (Figures 4 and 5). The features were those of a subareolar sclerosing duct papillomatosis (florid papillomatosis of the nipple). The presence of solid areas with central necrosis and similar