Extremely aggressive behavior of central giant cell granuloma after biopsy:a case report

Although central giant cell granulomas (CGCGs) appear to be benign, their radiographic findings are active. These tumors become severely invasive with the stimulus of surgery, resembling malignant tumors. Achieving the correct diagnosis is reportedly difficult because CGCGs are very similar to odontogenic jaw tumors. We herein describe an intriguing case of a 21-year-old male patient who was referred to our outpatient clinic with persistent swelling of the left buccal region. After making a provisional diagnosis of ameloblastoma from panoramic and computed tomography images, a biopsy was performed. Nine days after this operation, the intraoral lesion started to enlarge, causing facial disfigurement. Soon afterward, this lesion was examined by computed tomography, magnetic resonance imaging, and by both bone and tumor scintigraphy. Segmental resection of the mandible was conducted in the hospital, and the histopathological appearance was consistent with CGCG. Although CGCG tends to be indolent, the present case suggests that the stimulus of surgery can trigger clinically invasive behavior more characteristic of malignancy. CGCG exhibits variable features, but with the stimulus of surgery, its clinical behavior becomes extremely invasive, resembling a malignant tumor. The CGCG in the present case showed unusual development and intriguing radiographic and histopathological findings. It is important to be aware of the findings that can help to achieve a correct diagnosis.