Pathology · patient case question
Which cell is primarily responsible for producing the radiographic pattern seen in this patient?
Patient case: Bilateral jaw expansion in a young child
Patient: Male, 6 years old
Chief complaint: "His cheeks have been getting fuller on both sides for about a year. It does not hurt him."
History: Otherwise healthy. No trauma, no fever, no weight loss. The father was told as a child that he had "chubby cheeks" that settled on their own during his teens.
Findings: Painless, firm, bilaterally symmetric expansion of the posterior mandible. Lymph nodes not enlarged. Panoramic and PA radiographs show bilateral, symmetric, expansile multilocular radiolucencies of the mandible with displaced and unerupted teeth.
Show answer and explanation
Correct answer: B. Osteoclasts
- A. Osteoblasts DEPOSIT bone. They are recruited later, during the reparative phase after puberty when the lesions fill in with bone — but they do not create the radiolucency.
- B. CORRECT. Cherubism is driven by an SH3BP2 mutation that produces hyperactive OSTEOCLAST signalling through the RANK/RANKL pathway. The lesions consist of vascular fibrous tissue packed with multinucleated OSTEOCLAST-type giant cells, and it is their resorption of bone that carves out the multilocular radiolucent spaces seen on the film.
- C. Odontoclasts resorb dental hard tissue (root resorption, shedding of primary teeth). Teeth in cherubism are displaced and unerupted, but the radiolucency is BONE loss, not tooth loss.
- D. Odontoblasts form DENTIN within the tooth. They have no role in the resorption of jaw bone and could not produce a radiolucent bone pattern.
Note: Histologically the giant-cell lesion of cherubism is indistinguishable from central giant cell granuloma and from the brown tumour of hyperparathyroidism. Bilateral symmetry plus the age of onset is what makes the diagnosis, not the biopsy.