The most common malignancy that originates from the salivary gland is mucoepidermoid carcinoma (MEC), and it accounts for 15% of salivary gland tumors. One-third of all juvenile salivary gland tumors are malignant neoplasms. MEC accounts for 51% of malignant tumors and 16% of all salivary gland neoplasms in children (1, 2). Studies have reported that its prevalence is higher in females, and more than two-thirds of cases are found in the Parotid gland. Submandibular and sublingual salivary glands range between 8-23% and 2-4% of the cases, respectively (3). Mucoepidermoid carcinoma usually contains varying amounts of three types of cells including mucus cells, intermediate cells and epidermoid (squamoid) cells (4). However, aspiration of satisfactory material comprising of all three types of cells may not be feasible in every case of mucoepidermoid carcinoma. As a result, in complex cases, a strong clinicoradiological correlation, high index of suspicion, and repeat aspirations, particularly in cystic lesions, can be particularly beneficial. Furthermore, when dealing with low-cellularity mucinous cystic lesions, the need for early excision should be highlighted to the practitioner, as low-grade mucoepidermoid carcinoma cannot be ruled out in such cases (5).

In cases of aspirations containing only mucoid fluid, it is suggested to categorize the lesion into the diagnostic category of atypia of undetermined significance (AUS) in the Milan System for reporting salivary gland cytopathology. This diagnostic category's purpose is to lower the number of false-negative results in the non-neoplastic category and false-positive results in the neoplasm category. Reactive and reparative atypia, low cellularity samples that are suggestive but not definitive of a neoplasm, cystic lesions with extensive mucus and/or a minimal epithelial component, and parotid gland aspirates indeterminate for a lymphoproliferative disease include examples that can be put in this category (6). Molecular testing of mucoepidermoid carcinoma has clinical and histopathological relevance. The CRTC1 (MECT1)-MAML2 fusion gene resulting from t(11;19) (q14-21;p12-13) translocation, is characteristic of mucoepidermoid carcinoma. In this fusion gene, CREB-binding domain of the CREB coactivator MECT1 (also known as CRTC1) is fused to the transactivation domain of the Notch coactivator MAML2. This characteristic fusion gene is a valuable marker in determining the biological behavior of the tumor (7) (8).