Department of Pathology, Sichuan Cancer Hospital & Institute, Chengdu, 610041, Sichuan, China.
Department of Pathology, Affiliated Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, Sichuan, China.
Sci Rep. 2022 May 19;12(1):8504. doi: 10.1038/s41598-022-12583-w.
Adenoid cystic carcinoma (AdCC) of the breast is a rare indolent carcinoma of salivary gland-type tumors, frequently associated with MYB genetic alteration. Solid and basaloid adenoid cystic carcinoma (SB-AdCC) is considered a sparse variant of AdCC. This study sought to search for clinicopathological and genomic features in SB-AdCC. Registered clinicopathological data on a cohort of 13 AdCC of the breast cases, including six conventional adenoid cystic carcinoma (C-AdCC) cases and seven SB-AdCC cases, were collected. MYB gene rearrangement via fluorescent in situ hybridization was investigated and MYB protein expression was evaluated by immunohistochemistry. Compared with C-AdCC, we found that the distribution of SB-AdCC cases were shifted to older age and were more frequently distant metastasis. Moreover, metastasis cases also showed a high (exceed 30%) Ki-67 index. Both groups showed MYB rearrangements and MYB protein expression, but they were less frequent in SB-AdCC than C-AdCC. To conclude, our results suggest that SB-AdCC is an aggressive variant of mammary AdCC with a higher incidence of distant metastases compared with C-AdCC, though they share common molecular features. A high Ki-67 index may be an adverse prognostic factor for metastasis.
乳腺腺样囊性癌（AdCC）是一种罕见的、具有惰性的唾液腺型肿瘤，常与 MYB 基因改变有关。实性和基底细胞样腺样囊性癌（SB-AdCC）被认为是 AdCC 的稀疏变体。本研究旨在探讨 SB-AdCC 的临床病理和基因组特征。本研究收集了包括 6 例常规腺样囊性癌（C-AdCC）和 7 例 SB-AdCC 在内的 13 例乳腺 AdCC 病例的注册临床病理数据。通过荧光原位杂交检测 MYB 基因重排，并用免疫组织化学评估 MYB 蛋白表达。与 C-AdCC 相比，我们发现 SB-AdCC 病例的分布向老年转移，并且更频繁地发生远处转移。此外，转移病例的 Ki-67 指数也较高（超过 30%）。两组均显示 MYB 重排和 MYB 蛋白表达，但在 SB-AdCC 中比 C-AdCC 更为少见。总之，我们的研究结果表明，与 C-AdCC 相比，SB-AdCC 是一种侵袭性更强的乳腺 AdCC 变体，远处转移的发生率更高，尽管它们具有共同的分子特征。高 Ki-67 指数可能是远处转移的不良预后因素。
