Oncocytic sialolipoma of the submandibular gland with sebaceous differentiation: A new pathological entity

Case Report: We report the case of an oncocytic sialolipoma of the submandibular gland with sebaceous differentiation in a 73-year-old man. The initial symptom was a right submandibular painless mass. Ultrasonography showed a hypoechoic oval mass posterior to the submandibular gland. The tumorectomy was performed with preservation of the salivary gland. The tumor was composed of mature adipose tissue surrounded by a thin fibrous capsule, multiple nodules of oncocytes, normal ductal-acinar units with focal ductal sebaceous differentiation. Discussion: We reviewed literature of the reported cases of mixed tumors of the salivary glands composed of mature adipose tissue with oncocytosis, salivary ducts, and acini with sebaceous differentiation. Conclusions: Sialolipoma and lipoadenoma with or without oncocytosis and/or sebaceous differentiation should be considered organ-specific tumors with a distinct histological appearance and specific terminology