Características patológicas y perfiles de biomarcadores del carcinoma de mama microinvasivo diagnosticado en biopsia...

This study aims to describe the pathologic features and biomarker profiles of a large microinvasive breast carcinoma (MiBC) cohort diagnosed on biopsy (CNB) and compare these findings with corresponding tumors on excision. Out of 263 MiBC, approximately half of the DCIS cases were classified as high-grade. On CNB, ER, PR, and HER2 were positive in 166/226 (73%), 124/225 (55%), and 48/174 (28%) of the tested cases, respectively. Excision specimens from 132 cases revealed invasive carcinoma in 52/132 (39%), MiBC in 31/132 (23%), DCIS only in 35/132 (27%), LCIS only in 4/132 (3%), and benign findings in 10/132 (8%). The concordance rates between CNB and excision were initially 100% for ER (40/40), 95% for PR (38/40), and 90% for HER2 (26/29). While routine retesting of ER/PR may not be necessary in cases of MiBC on CNB, selective repeat HER2 testing should be considered when larger tumors are present on excision.