Swelling of the submandibular gland region: Cystic or neoplastic entity?

A 43-year-old male patient reported with a swelling in the left submandibular region of 3-4 months' duration. The soft fluctuant swelling was painless and cystic on palpation. The excised submandibular gland was submitted for histopathological examination, which showed the presence of a bluish, thin-walled cystic cavity containing gelatinous straw-colored fluid. H and E-stained sections showed thin cystic lining with papillary projections of salivary glandular cells and multiple cystic spaces. Immunohistochemistry was recommended to differentiate between acinic cell carcinoma of papillary-cystic variant and low-grade mucoepidermoid carcinoma.