Basal cell adenomas are uncommon salivary gland tumors, representing ~4% (range 1-7.5%) of benign parotid tumors. They can also occur in the other major salivary glands as well as the minor salivary glands.
Most commonly, a painless growing mass 1.
Typically, basal cell adenomas are unilateral, round/oval and <3 cm 1.
Imaging features are similar to pleomorphic adenomas, although basal cell adenomas are more likely to have smooth margins compared to the undulating margins typical of pleomorphic adenomas >1 cm in size 2.
ADC values are typically lower in basal cell adenomas compared to pleomorphic adenomas (1.24 vs 1.86 10−3 mm2 s−1 in one study 1) and they appear slightly more cystic 1.
Basal cell adenoma can degenerative into basal cell adenocarcinoma, although these are reported to more commonly arise de novo 2.
- 1. Mukai H, Motoori K, Horikoshi T, Takishima H, Nagai Y, Okamoto Y, Uno T. Basal cell adenoma of the parotid gland; MR features and differentiation from pleomorphic adenoma. (2016) Dento maxillo facial radiology. 45 (4): 20150322. doi:10.1259/dmfr.20150322 - Pubmed
- 2. Wilson TC, Robinson RA. Basal cell adenocarcinoma and Basal cell adenoma of the salivary glands: a clinicopathological review of seventy tumors with comparison of morphologic features and growth control indices. (2015) Head and neck pathology. 9 (2): 205-13. doi:10.1007/s12105-014-0562-4 - Pubmed
- 3. Lu J, Zhang W, Wang Z, Jia H, Ma Y, Wu H, Xiang M. Basal cell adenoma of the parotid gland: clinical and pathological findings in 29 cases. (2015) International journal of clinical and experimental pathology. 8 (3): 2899-908. Pubmed