Mucoepidermoid carcinoma lacking squamous component arising in rare location: utility of MAML2 genetic testing for...

Salivary gland malignancies are rare, accounting for less than 5% of head and neck cancers. Mucoepidermoid carcinoma (MEC) is the most common salivary gland tumour, predominantly found in the parotid gland. However, it has rarely been reported in the tongue. Histologically, these tumours typically exhibit a combination of mucous, squamous and intermediate cell components. In the 2022 version of the WHO classification of salivary gland tumours, MAML2 rearrangement is desirable but not essential for diagnosis. In rare cases, MEC may lack a squamous component, posing diagnostic challenges. In such cases, MAML2 rearrangement is crucial for diagnosis. We present a unique case of a man in his 60s with a MEC arising in the tongue with predominantly clear cells and devoid of squamous components. This case emphasises the critical role of MAML2 genetic testing in achieving an accurate diagnosis in rare locations with unusual morphology.