A child has painless bilateral mandibular enlargement over the last year. Calcium/phosphate are normal. Histopathology reveals giant cells. What is the diagnosis?

Correct answer: C. Cherubism

• A. Paget's is rare in children and shows elevated alkaline phosphatase — not normal calcium/phosphate with painless bilateral jaw enlargement.
• B. CGCG is typically unilateral — bilateral presentation in a child with normal labs points to cherubism.
• C. Cherubism is a self-limiting, autosomal dominant condition causing BILATERAL jaw enlargement in childhood, with normal calcium/phosphate. Histologically it shows giant cells in fibrous stroma. Unlike Brown tumor (hyperparathyroidism), calcium and phosphate are NORMAL.
• D. Brown tumor is caused by hyperparathyroidism, which shows ELEVATED calcium and decreased phosphate. Normal labs rule this out.