大细胞钙化Sertoli细胞瘤（LCCSCT）是一种睾丸性索-间质瘤，可能在散发性或Carney综合征及其他遗传综合征的情况下发生。其某些亚型具有临床恶性特征，而推动这种侵袭性行为的分子机制尚不清楚。方法和结果：我们使用PRKAR1A免疫组化（IHC）和下一代测序分析了20名LCCSCT患者（12个非转移和8个转移）的21个样本。除两个（案例17和20，两个都是转移型）外，所有肿瘤均表现出PRKAR1A表达丧失。在解释性测序结果可行的11个病例中，所有病例都携带了PRKAR1A的致病单核苷酸变异。对于所有具有可解释杂合性数据的肿瘤，都存在PRKAR1A等位基因丧失的证据，但非转移性和转移性肿瘤的LOH机制不同。非转移性肿瘤仅表现为拷贝中性LOH，而转移性肿瘤表现出LOH的不同机制谱，包括拷贝损失LOH、两个并发突变或拷贝中性LOH。非转移性LCCSCT的相关分子发现仅限于PRKAR1A变异。相反，所有具有可解释数据的转移性LCCSCT都携带了其他致病变异，包括但不限于带有LOH证据的BRCA2变异和双等位基因CDKN2A / B缺失。三名患者携带推断出的PRKAR1A家系起源变异，其中包括一个Carney综合征患者和两个没有已知综合征特征的患者。结论：本研究进一步证实PRKAR1A IHC是非转移性和转移性肿瘤的有用诊断工具，并建议分子分析可以帮助在选定患者中识别具有恶性潜力的非转移性肿瘤。重要的是，这些结果强调了对所有LCCSCT患者进行遗传评估可能是有益的。© 2023 John Wiley＆Sons Ltd。

Large cell calcifying Sertoli cell tumour (LCCSCT) is a type of testicular sex cord-stromal tumour that may occur sporadically or in the context of Carney complex and other genetic syndromes. A subset is clinically malignant, and the molecular mechanisms that drive such aggressive behaviour remain unknown. METHODS AND RESULTS: We analysed 21 samples from 20 patients with LCCSCT (12 non-metastasising and eight metastasising) using PRKAR1A immunohistochemistry (IHC) and next-generation sequencing. All tumours except two (cases 17 and 20, both metastasising) demonstrated loss of PRKAR1A expression. Among 11 cases with interpretable sequencing results, all harboured pathogenic single nucleotide variants of PRKAR1A. Evidence of loss of heterozygosity (LOH) of PRKAR1A was present in all tumours with interpretable zygosity data, but the mechanisms of LOH were different for non-metastasising and metastasising tumours. Non-metastasising tumours demonstrated only copy-neutral LOH, while metastasising tumours demonstrated a spectrum of mechanisms of LOH, including copy-loss LOH, two concurrent mutations or copy-neutral LOH. Relevant molecular findings in non-metastasising LCCSCT were limited to PRKAR1A variants. In contrast, all metastasising LCCSCTs with interpretable data harboured additional pathogenic variants, including (but not restricted to) BRCA2 mutations with evidence of LOH and bi-allelic CDKN2A/B deletions. Three patients harboured PRKAR1A variants of inferred germline origin, including one with Carney complex and two without known syndromic features. CONCLUSIONS: This study further confirms that PRKAR1A IHC is a useful diagnostic tool for both non-metastasising and metastasising tumours and suggests that molecular analyses can be helpful to identify non-metastasising tumours with malignant potential in selected patients. Importantly, these results highlight that germline assessment could be beneficial for all patients presenting with LCCSCT.© 2023 John Wiley & Sons Ltd.