Peripheral Giant Cell Granuloma Mimicking Central Giant Cell Granuloma in a Pediatric Patient: A Diagnostic Challenge.

INTRODUCTION: Peripheral giant cell granuloma (PGCG) is a benign reactive lesion that typically arises from the gingiva or edentulous alveolar ridge. Although superficial pressure resorption of the underlying bone has been described, extensive cortical erosion mimicking a central giant cell granuloma (CGCG) is exceptionally uncommon, particularly in pediatric patients, creating a significant diagnostic challenge. CASE PRESENTATION: A 10-year-old boy presented with an exophytic gingival mass involving the right mandibular alveolar ridge. Although the lesion appeared clinically peripheral, cone-beam computed tomography demonstrated a 40 × 25 mm expansile osteolytic lesion with cortical bone erosion, involvement of adjacent developing teeth, and imaging findings suggestive of CGCG. Incisional biopsy revealed features consistent with PGCG. Laboratory investigations, including serum calcium, phosphorus, alkaline phosphatase, and parathyroid hormone levels, were within normal limits, excluding hyperparathyroidism. Complete surgical excision with peripheral osteotomy was performed under general anesthesia, and histopathological examination of the excised specimen confirmed the diagnosis of PGCG. CONCLUSION: This case illustrates that PGCG may rarely present with cortical bone erosion and radiographic findings closely resembling CGCG. Accurate diagnosis requires integration of clinical examination, advanced imaging, histopathological evaluation, and laboratory investigations rather than reliance on a single diagnostic modality. Recognition of this uncommon presentation may prevent misdiagnosis and avoid unnecessarily aggressive treatment in pediatric patients.