Fibrous dysplasia of the maxillary bone secondary to sinus surgery in an elderly patient: A case report.

Fibrous dysplasia (FD) is a rare benign disease that replaces a normal bone with abnormal fibrous and weak osseous tissue. It is usually detected in childhood and rarely occurs in old age. Although the disease is known to be caused by a genetic mutation, only a single case of FD secondary to surgery is reported in the literature. We report a case of monostotic FD of the maxillary sinus in a 70-year-old Asian woman who presented with incidental calcific lesion in the maxillary sinus on a brain computed tomography scan. At 32 months prior to presentation, the patient had undergone an endoscopic sinus surgery for a fungal ball of the same sinus. The lesion was removed by endoscopic surgery, and the histopathological evidence was consistent with FD. To the best of our knowledge, this is the second case of a postsurgical craniofacial FD, and a rare case that occurred in old age.