Complex sclerosing lesions of the breast:a clinicopathological analysis of 36 cases

WU Wenya; BAI Jun; SU Yajie

doi:10.3969/j.issn.1007-8096.2025.08.003

Abstract：Objective To investigate the clinicopathological features,diagnosis and differential diagnosis of complex sclerosing lesions(CSL)of the breast.Methods The clinical data of 36 cases of CSL diagnosed and treated in our hospital from January 2009 to January 2025 were collected.The clinicopathological features and immunophenotype were analyzed,and the relevant literature was reviewed.Results The age of 36 patients ranged from 29 to 73 years,with a median age of 47 years.All patients were female.There were 35 patients with a breast mass and 1 patient with nipple discharge.Core needle biopsy was performed in 24 cases,and the diagnosis was confirmed in only 6 cases.The 33 cases of CSL were complex type,with morphological changes of interstitial fibrosis and sclerosis,accompanied by varying degrees of proliferative lesions and pseudoinvasive changes.Three cases were variant type with irregular scar area.Six cases were accompanied by low-grade ductal carcinoma in situ,including 1 case with apocrine gland type,4 cases with atypical hyperplasia,and 1 case with invasive lobular carcinoma and lobular carcinoma in situ.Immunohistochemically,the tumor cells showed a mosaic expression of CK5/6,variable positivity of ER and PR,and discontinuous expression of SMMHC around the proliferative ducts.The differential diagnosis was mainly from invasive carcinoma.Conclusions The morphology of CSL is variable and prone to be misdiagnosed.Complete resection of the mass and immunohistochemical staining play an important role in the diagnosis and differential diagnosis.