Fibrous Dysplasia Developed at the Site of a Previous Central Giant Cell Granuloma in a Middle-Aged Patient: A Case...

Fibrous dysplasia (FD) is a benign fibro-osseous condition, characterized by replacement of normal bone with immature fibrous tissue due to GNAS mutations, whereas central giant cell granuloma (CGCG) is a reactive lesion featuring multinucleated giant cells in a vascular stroma. Although some hybrid lesions combining FD and CGCG have been reported as synchronous entities, metachronous occurrences, where FD develops years after CGCG excision, are rare. This report describes a case of metachronous FD arising at the site of a previously excised CGCG after a 10-year interval, exploring potential temporal association and emphasizing the need for extended follow-up.

A 50-year-old woman presented with a firm, gradually enlarging swelling in the right maxilla that had developed over 2 years. Her history included surgical excision of a pure CGCG (no fibro-osseous elements) in the same location 10 years prior. Clinical examination revealed bony-hard expansion without neurosensory deficits or lymphadenopathy. Cone-beam computed tomography showed a poorly defined, expansile radiopaque mass with a ground-glass pattern, obliterating the maxillary sinus. An incisional biopsy showed evidence of FD, with irregular woven bone trabeculae in fibrous stroma lacking osteoblastic rimming.

To the best of our knowledge, this is one of the first reported metachronous cases of FD arising de novo at the site of a previously excised CGCG following a 10-year interval. This report underscores the importance of long-term follow-up for patients with jaw pathologies to detect rare sequential developments.