Xu Bin, Viswanathan Kartik, Afkhami Michelle, Mikula Mike, Lubin Dan, Magliocca Kelly, Roy Dibisha, Ghossein Ronald, Bell Diana, Rooper Lisa, Katabi Nora
Department of Pathology and Laboratory Medicine, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY, 10065, USA.
Department of Pathology and Laboratory Medicine, School of Medicine, Emory University, Atlanta, GA, USA.
Virchows Arch. 2025 Jul 2. doi: 10.1007/s00428-025-04159-6.
Epithelial-myoepithelial carcinoma (EMC) may occur de novo or ex pleomorphic adenoma (PA). We aimed to investigate the prognostic and clinicopathologic features and the utility of RAS Q61R immunohistochemistry in a multicenter retrospective cohort of 75 EMCs. Seven tumors (9%) were EMC ex PA, whereas 91% (n = 68) were EMC de novo. Compared with EMC de novo, EMC ex PA was associated with a significant higher percentage of hyalinized and myxoid stroma, larger tumor size, frequent perineural invasion (PNI), absence of nuclear enlargement, and lower frequency of pT1 disease. Seven out of 65 patients had adverse events (five local recurrence, two regional recurrences, two distant metastases, and two disease-related death). The 5-year and 10-year disease-specific survival were 100% and 91% respectively, and the 5-year and 10-year disease-free survival (DFS) were 90% and 85% respectively. Adverse pathologic features that were associated with RFS on univariate survival analysis included PNI, atypical mitosis, mitotic count, and tumor size ≥ 4 cm. Among them, PNI and atypical mitosis remained as independent prognostic factors on multivariate survival analysis. The frequency of RAS Q61R immunopositivity was 31% (12/39) in EMC de novo, 0% (0/5) in EMC ex PA, and 0% (0/32) in non-EMC salivary neoplasms. In conclusion, although most of the EMCs are de novo, 9% are EMCs ex PA. PNI, mitotic index, atypical mitosis, and large tumor size predict shortened RFS in EMC. RAS Q61R immunopositivity is highly specific for EMC de novo and is absent in EMC ex PA.
上皮-肌上皮癌（EMC）可原发发生或由多形性腺瘤（PA）恶变而来。我们旨在研究75例EMC多中心回顾性队列中的预后和临床病理特征以及RAS Q61R免疫组化的应用价值。7例肿瘤（9%）为PA恶变而来的EMC，而91%（n = 68）为原发EMC。与原发EMC相比，PA恶变而来的EMC中玻璃样变和黏液样间质的比例显著更高、肿瘤更大、神经周侵犯（PNI）常见、无核增大且pT1期疾病频率更低。65例患者中有7例发生不良事件（5例局部复发、2例区域复发、2例远处转移和2例疾病相关死亡）。5年和10年疾病特异性生存率分别为100%和91%，5年和10年无病生存率（DFS）分别为90%和85%。单因素生存分析中与无复发生存期（RFS）相关的不良病理特征包括PNI、非典型有丝分裂、有丝分裂计数和肿瘤大小≥4 cm。其中，PNI和非典型有丝分裂在多因素生存分析中仍为独立预后因素。原发EMC中RAS Q61R免疫阳性频率为31%（12/39），PA恶变而来的EMC中为0%（0/5），非EMC唾液腺肿瘤中为0%（0/32）。总之，虽然大多数EMC是原发的，但9%是PA恶变而来的EMC。PNI、有丝分裂指数、非典型有丝分裂和大肿瘤大小提示EMC的RFS缩短。RAS Q61R免疫阳性对原发EMC具有高度特异性，PA恶变而来的EMC中不存在。
