Fig. 1: Histologic and clinicopathologic features of breast carcinomas associated with microglandular adenosis.

A Case 2, a 46 year-old BRCA1 c.181 T > G carrier with matrix-producing metaplastic carcinoma associated with atypical microglandular adenosis (B). Case 35, a 32 year-old with invasive carcinoma showing acinic cell features and associated atypical microglandular adenosis. Prominent granules in acinic cell-like areas merge with invasive carcinoma (C) Case 6, a 47 year-old BRCA1 c.3607 C > T carrier with invasive ductal carcinoma of no special type and adjacent breast carcinoma (in situ) associated with MGA (BCis-MGA) and atypical microglandular adenosis (2X) Areas of frank invasion transition from BCis-MGA (D) Oncoplot illustrating the germline pathogenic/likely pathogenic variants in patients along with their associated clinicopathologic characteristics. Stacked bar plots showing comparison of clinicopathologic features between HRD germline carriers and sporadic tumors, including tumor infiltrating lymphocytes (TILs; E), % of response (pCR) to neoadjuvant chemotherapy (F), and histologic type (G). HRD homologous recombination deficiency, VUS variant of unknown significance, IDC-NST invasive ductal carcinoma of no special type, BCis-MGA breast carcinoma (in situ) associated with microglandular adenosis, TILs tumor infiltrating lymphocytes, pCR pathologic complete response.