Warthin tumour is the second most common benign neoplasm of salivary glands. Despite its relatively characteristic histology, it may sometimes mimic other lesions. Here, we report two female non-smoker patients diagnosed with low-grade mucoepidermoid carcinoma with oncocytic epithelium and prominent lymphoid (Warthin-like) stroma and with molecularly confirmed MAML2 rearrangement. In addition, we screened a consecutive series of 114 Warthin tumour cases by means of MAML2 break apart fluorescence in situ hybridization to assess its value in differential diagnosis. MAML2 rearrangement was detected in both mucoepidermoid carcinoma cases, while all Warthin tumours were negative. Taking into account the literature data, Warthin-like mucoepidermoid carcinomas are more frequently observed in women, while a slight male predominance and smoking history are typical for Warthin tumour. In addition, the patients with Warthin-like mucoepidermoid carcinoma were significantly younger than those with Warthin tumour. To conclude, Warthin-like mucoepidermoid carcinoma may usually be suspected based on histology, while the diagnosis can be confirmed by means of molecular assays such as FISH. The investigation of MAML2 status is particularly advised when Warthin tumour is considered in a young, non-smoking, female patient.

Warthin肿瘤是唾液腺的第二大最常见的良性肿瘤。尽管其组织学具有相对特征性，但有时仍可模仿其他病变。在这里，我们报告了两名女性非吸烟患者，他们被诊断患有低级粘液表皮样癌，具有上皮性上皮细胞和突出的淋巴样（Warthin样）基质，并经过分子确证的MAML2重排。此外，我们通过MAML2分离荧光原位杂交技术连续筛选了114例Warthin肿瘤病例，以评估其在鉴别诊断中的价值。MAML2在两个粘液表皮样癌病例中均检测到重排，而所有Warthin肿瘤均为阴性。考虑到文献数据，女性更常观察到Warthin样粘液表皮样癌，而Warthin肿瘤的典型特征是轻微的男性优势和吸烟史。此外，Warthin样粘液表皮样癌的患者比Warthin肿瘤的患者年轻得多。总而言之，根据组织学通常可怀疑沃辛样粘液表皮样癌，而诊断可通过分子检测如FISH进行确认。当在年轻的非吸烟女性患者中考虑Warthin肿瘤时，特别建议对MAML2状态进行调查。