BRCA1相关蛋白1（BAP1）是一个肿瘤抑制基因，在各种肿瘤以及BAP1肿瘤易感综合征中发生改变。BAP1的变异与某些恶性肿瘤的侵袭性行为有关，并可能在未来的治疗中具有治疗意义。我们提出了首例证明BAP1蛋白通过免疫组织化学在涎管癌（SDC）组分中的表达丧失的病例，该病例是在分子功能丧失的背景下的包膜内型多形性腺瘤癌变（CXPA）的病例。 一名约55岁的女性患者出现深部腮腺叶肿块，进行了切除手术，发现为CXPA。进行了BAP1免疫组织化学和下一代测序以进一步表征该肿瘤。结果显示，该肿瘤在SDC组分中丧失了BAP1蛋白的表达，但在残留的多形性腺瘤（PA）中保留了。下一代测序确认了该肿瘤中BAP1功能丧失的变异。这是首例CXPA中SDC组分中BAP1蛋白表达丧失的病例报告。需要进行未来的研究，以探讨BAP1变异在SDC和CXPA中的相关性，这可能具有预后和治疗意义。© 2023. 版权所有 作者，独家许可 Springer Science+Business Media, LLC，属于 Springer Nature。

BRCA1-associated protein 1 (BAP1) is a tumor suppressor gene that is altered in a variety of neoplasms as well as in BAP1 tumor predisposition syndrome. BAP1 alterations are associated with aggressive behavior in some malignancies and may have treatment implications in future. We present the first documented case of loss of BAP1 protein expression by immunohistochemistry in the salivary duct carcinoma (SDC) component of an intracapsular carcinoma ex pleomorphic adenoma (CXPA) in the context of molecular loss of function of BAP1 in the neoplasm.A woman of approximately 55 years of age presented with a deep parotid lobe mass, which was resected and found to be CXPA. BAP1 immunohistochemistry and next-generation sequencing was performed to further characterize the neoplasm.The neoplasm showed loss of BAP1 protein expression in the SDC component but retention in the residual pleomorphic adenoma (PA). Next-generation sequencing confirmed a BAP1 loss of function alteration in the neoplasm.This is the first documented case report of BAP1 protein expression loss in the SDC component of a CXPA. Future studies are needed to investigate the relevance of BAP1 alterations in SDC and CXPA, which may have prognostic and treatment implications.© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.