Cysts, Benign Tumors and Salivary Gland Pathology
This domain tests differential diagnosis, biopsy strategy and recurrence risk.
Core rules
- Odontogenic cysts include radicular, dentigerous, odontogenic keratocyst, lateral periodontal and glandular cysts.
- Odontogenic keratocyst has a high recurrence rate; treatment ranges from enucleation with adjuncts to resection. Ameloblastoma is locally aggressive; unicystic versus solid multicystic disease changes management.
- Benign salivary tumors include pleomorphic adenoma, usually in the parotid and treated by superficial parotidectomy with facial nerve preservation; Warthin tumor, often in the parotid tail and associated with smoking; and mucoepidermoid carcinoma, which can arise in minor glands of the palate.
- Red flags include a fixed mass, facial nerve palsy, rapid growth, pain, ulceration and cervical nodes.
- Fine-needle aspiration is useful but not definitive; histology is required.
Worked example
A 30-year-old has a multilocular radiolucency at the mandibular angle with an impacted 38. The differential includes ameloblastoma, odontogenic keratocyst and odontogenic myxoma. Obtain CT and incisional biopsy; if ameloblastoma is confirmed, segmental resection with margins is preferred over simple enucleation.
Traps
Enucleating a large lesion without diagnosis; missing a second keratocyst; calling every parotid mass a pleomorphic adenoma; not assessing facial nerve function.