[Zuska's disease of the breast: a clinicopathological analysis of 315 cases]

Objective: To investigate the clinicopathological characteristics of Zuska's disease of the breast. Methods: A total of 315 cases of breast Zuska's disease diagnosed from December 2018 to December 2025 were collected from the Seventh Medical Center of the People's Liberation Army General Hospital, Dongzhimen Hospital of Beijing University of Chinese Medicine, and the First Affiliated Laohekou Hospital of Hubei University of Arts and Science. HE staining was performed for the specimens, and the clinicopathological characteristics of these cases were analyzed and summarized. Results: Among the 315 patients, 306 were female and 9 were male, with an age of 31.0 (23.4,38.7) years. Clinically, viscous nipple discharge was often the initial symptom. Gross examination of the resected specimens of the breast lesion showed ulceration of skin. The cut surface of the lesion revealed significantly ductal dilatation, with secretions inside the ducts. Histologically, lactiferous ducts showed cystic dilatation with squamous metaplasia and hyperplasia. The lumens contained abundant acute, chronic inflammatory cells and keratin debris. There were extensive mixed inflammatory cell infiltration and fibrosis around the ducts. In later stages, the lactiferous duct centrically, subareolar abscess was developed. Conclusions: Mammary Zuska's disease is histopathologically characterized by squamous metaplasia of the lactiferous ducts, intraductal keratin accumulation, and periductal suppurative inflammation. A small subgroup of cases may be complicated by squamous cell carcinoma.