A 7-year-old girl has several missing teeth and bilateral expansion of the maxilla and mandible. The panoramic radiograph shows bilateral multilocular radiolucencies with displaced and unerupted teeth. What is the diagnosis and its inheritance pattern?

Correct answer: B. Cherubism — autosomal dominant

• A. Gorlin syndrome is autosomal DOMINANT, its keratocysts are usually not symmetric in this pattern, and it presents with basal cell carcinomas, palmar pits and calcification of the falx cerebri.
• B. CORRECT. CHERUBISM is an AUTOSOMAL DOMINANT condition caused by mutations in SH3BP2, producing bilaterally symmetric, expansile MULTILOCULAR radiolucencies of the jaws. It presents in childhood, typically between 2 and 7 years, with painless symmetric facial fullness, displaced and unerupted teeth, and often agenesis of the second and third molars. Lesions expand until puberty and then regress.
• C. Fibrous dysplasia is indeed a sporadic somatic GNAS mutation, but it is typically UNILATERAL and produces a ground-glass radiopacity with poorly defined margins — not bilateral multilocular radiolucencies.
• D. The inheritance is dominant, not X-linked. Penetrance is close to complete in males and somewhat reduced in females.

Note: The bilateral symmetry is what makes this diagnosis. Histology shows multinucleated giant cells in a fibrous stroma, indistinguishable from central giant cell granuloma — so the radiographic pattern and family history, not the biopsy, make the call. Management is conservative and observational in most cases, since spontaneous regression after puberty is the rule.