Abstract
Fibrous dysplasia has a concept that occurs in three forms as follows: (1) monostotic fibrous dysplasia which appears only in a single bone, (2) polyostotic fibrous dysplasia observed in several bones usually in a unilateral destribution or in the whole body skeleton, and (3) Albright's Syndrome with the pigmentation of the skin.
In the past, differential diagnoses of these forms were carried out usually with conventional radiography. Recently, bone scintigraphy with 99mTc labeled phosphate complex has become utilized as a useful modality in differentiating polyostotic fibrous dysplasia from monostotic fibrous dysplasia.
A case of fibrous dysplasia is presented which was diagnosed to be polyostotic (or craniofacial) fibrous dysplasia on the results of bone scintigraphy with 99mTc labeled methylene diphosphonate.
The patient was a 24-year-old woman admitted to the Department of Dental Radiology, Higashi Nippon Gakuen University, with the chief complaint of a painless monocystic lesion in the right mandible and an expansible bony lesion in the right maxilla. No noteworthy events were seen in her family history and the past history of her own.
The intra-oral radiographs showed a monocystic lesion in the right mandible and an osseous lesion with a ground-glass appearance in the right maxilla.
The panoramic radiograph demonstrated a remarkable enlargement of the right mandible which was growing toward the ramus, and an increased radiopaque lesion in the right zygomatic arch. Right maxillary sinus was decreased in volume due to the growth of the bony lesion into the sinus.
The postero-anterior view of the skull revealed that the right nasal cavity was narrowed and that the right ethmoidal sinus became small due to the growth of the osseous lesions.
The spot scan images with 99mTc labeled methylen diphosphonate showed remarkably increased uptakes corresponding to the osseous lesions in the mandible, maxilla, zygomatic arch, maxillary sinus and ethmoidal sinus in the right side. The whole body scan images revealed no abnormalities in the whole body skeleton, except for the maxillofacial resions.
