salivary gland sebaceous tumors

Oral sebaceous glands

Sebaceous glands are commonly found in the parotid gland (10–42% of glands) and are found less frequently in the submandibular glands (5–6% of glands) using standard surgical pathology sampling techniques; however, they are only rarely seen in the sublingual gland or in parotid area lymph nodes.

Intraoral sebaceous glands, known as Fordyce granules, are found in up to 80% of individuals, most frequently on the buccal mucosa or vermilion border of the upper lip and less frequently in the retromolar and anterior tonsillar pillar region. These are considered a normal anatomic variant and may vary in number from a few to several hundred. In a recent study, the frequency of Fordyce granules was 50- to 90-fold greater in a population with hereditary non-polyposis colorectal cancer syndrome (HNPCC or Lynch syndrome) as compared to the general population, suggesting activation in this syndrome. Rarely, Fordyce granules may become hyperplastic. Sebaceous glands with fewer than 15 lobules are considered normal, while those with 15 or more lobules are considered hyperplastic.

Salivary gland sebaceous neoplasms are classified histologically into five groups:
 sebaceous adenoma,
 sebaceous lymphadenoma (SL),
 sebaceous carcinoma,
 sebaceous lymphadenocarcinoma,
 sebaceous differentiation in other tumors.

Although parotid and submandibular gland sebaceous differentiation is relatively common, sebaceous neoplasms in these locations are extremely rare.

The most frequent sebaceous tumor is SL followed by sebaceous carcinoma and sebaceous adenoma, with the least frequent being sebaceous lymphadenocarcinoma; in addition, various other salivary gland tumors have been associated with sebaceous differentiation.

Open references

 My journey into the world of salivary gland sebaceous neoplasms. Gnepp DR. Head Neck Pathol. 2012 Mar;6(1):101-10. doi : 10.1007/s12105-012-0343-x PMID: 22430772 (Free)