Clinicopathological features of adenoid cystic carcinoma of the breast / 肿瘤研究与临床

ABSTRACT

Objective:To investigate the clinicopathological characteristics, gene mutation and prognosis of adenoid cystic carcinoma of the breast (AdCC).Methods:A total of 12 cases of AdCC samples archived at Linyi Cancer Hospital from January 2008 to December 2021 were collected, including 8 cases of classic adenoid cystic carcinoma (C-AdCC) and 4 cases of solid-basaloid adenoid cystic carcinoma (SB-AdCC). Histomorphology, immunohistochemicstry and molecular genetics were performed to analyze the clinicopathological characteristics and the prognosis of AdCC.Results:C-AdCC patients grew in the shape of beam-tubuler and cribriform architecture, with characteristic structures of true and pseudoadenoid lumen; SB-AdCC patients grew in nests and solid, with moderate to severe atypia, necrosis and high mitotic count. Immunohistochemistry showed that CK7, CK5/6, p63 and S-100 were expressed in 8 cases of C-AdCC, and CD117 and CD10 were diffusely expressed in 4 cases of SB-AdCC. Fluorescence in situ hybridization (FISH) showed that 3 C-AdCC patients had MYB gene break. Next-generation sequencing (NGS) revealed NOTCH1 gene mutation was detected in 2 SB-AdCC patients. No lymph node metastasis was observed in 8 patients with C-AdCC, but 2 had postoperative lymph node metastasis in 4 patients with SB-AdCC.Conclusions:C-AdCC mainly grows in beam-tubular and sieve shape, with low-grade atypia and good prognosis. Some cases have MYB-NFIB fusion gene. SB-AdCC mainly shows nest-mass, solid growth, moderate to severe atypia, necrosis and mitosis (>5/10 high power field) as well as poor prognosis; some patients have NOTCH1 gene mutation.