An Extremely Rare Case of Synchronous Low-Grade Polymorphous Adenocarcinoma With Canalicular Adenoma of the Minor Salivary Gland of the Palate

Tumors of the salivary gland are a group of complex, heterogeneous lesions that are located either in the parotid gland, submandibular gland, sublingual gland, or minor salivary glands. These tumors have a wide range of etiology, pathophysiology, treatment, and prognosis. Multiple salivary gland tumors are extremely rare and usually occur more commonly in major salivary glands than in minor glands. A 61-year-old man with a chief complaint of swelling in the upper jaw for the past eight years reported to the department of oral and maxillofacial surgery. Incisional biopsy revealed a canalicular adenoma (CA) of the minor salivary gland of the palate. Wide local excision was done with closure using a buccal pad of fat and a collagen sheet. Surprisingly, the excisional biopsy was suggestive of synchronous low-grade polymorphous adenocarcinoma (PAC) with CA of the minor salivary gland of the palate. This appears to be the first reported case of PAC with CA found in the palate.