Breast papillary neoplasms include a wide range of tumor types, and their pathological diagnosis is sometimes difficult. Furthermore, the etiology of these lesions is still not fully understood. We report the case of a 72-years-old woman referred to our hospital with bloody discharge from the right nipple. An imaging study detected a cystic lesion, including a solid component contiguous with the mammary duct, in the subareolar region. The lesion was then removed by segmental mastectomy. Pathological examination of the resected specimen revealed an intraductal papilloma with atypical ductal hyperplasia. Moreover, the atypical ductal epithelial cells expressed neuroendocrine markers. The presence of an intraductal papillary lesion with neuroendocrine differentiation suggests solid papillary carcinoma. Thus, this case suggests that intraductal papilloma could be a precursor of solid papillary carcinoma.
Keywords: Atypical ductal hyperplasia; Breast cancer; Intraductal papilloma; Neuroendocrine differentiation; Solid papillary carcinoma.
© 2023. The Author(s) under exclusive licence to The Japanese Society for Clinical Molecular Morphology.