Metaplastic breast carcinoma: analysis of clinical and pathologic characteristics

[摘要] Background and objective: The novel multistep molecular model of breast carcinogenesis is based onthe oestrogen receptor (ER) status of the tumour. Its two main arms comprise ER-positive and ERnegative breast carcinomas (BCa), associated with different pre-neoplastic/high-risk proliferativeepithelial changes: columnar cell lesions (CCL), atypical ductal hyperplasia (ADH), lobular carcinomain-situ (LCIS), low-grade ductal carcinoma in-situ (LG-DCIS) with ER-positive tumours andmicroglandular adenosis (MGA), pleomorphic LCIS (PLCIS), high-grade DCIS (HG-DCIS) with ERnegative tumours. This study aims to describe the association between proliferative epithelial changesin tissue adjacent to BCa in Sri Lankan women in relation to the ER status of the tumour.Method: A descriptive cross-sectional study of 420 cases, including wide local excision andmastectomy specimens of BCa handled by the National Hospital of Sri Lanka, Colombo, between2017–2019. The tissue adjacent to BCa (within 10 mm distance from tumour) was histologicallyassessed for proliferative epithelial changes. Tumour ER status assessed by immunohistochemistrywas reviewed. The associations between proliferative epithelial changes and the ER status wereanalysed by univariate analysis.Results: ER-positive BCa (n=322) showed significant associations with columnar cell hyperplasia(27.32% vs 17.34%, p=0.04), flat epithelial atypia (16.77% vs 8.16%, p=0.035) and LG-DCIS(41.30%vs11.22%, p<0.001). PLCIS, though more frequent in ER-positive tumours, did not attainstatistical significance. ER-negative BCa (n=98) showed a significant association with HG-DCIS(43.87%vs30.74%, p=0.016). MGA was not detected.Conclusion: Pre-neoplastic/high-risk epithelial changes evaluated in tissue adjacent to BCa in our localsetting support the two recently described molecular models of BCa carcinogenesis. Identification ofthese proliferative epithelial components in a core biopsy that is negative for BCa should thereforeprompt the pathologist to advise the clinician on close clinicoradiological correlation, and if necessary,to perform a repeat biopsy of suspicious lesions.

[学科分类] 生理学与病理学