A case of ossifing fibroma of the mandible suspected as cystic lesion

Abstract

A case of ossifying fibroma of the mandible suspected as cystic lesion was reported. The patient was a 38 year-old female complaining of a swelling of the gingiva at the left lower molar region. X-ray examination showed a cystic radiolucent lesion at the left mandibular body, which included apices of left lower first and second molar. A biopsy was performed. The lesion had a unilocular cyst-like appearance with an extremely thin wall, and included light-yellowish, serous liquid. Histological diagnosis was ossifying fibroma, and surgical enucleation was carried out.
In the histological findings, the specimen showed spheroidal calcified deposits which were stained deeply by hematoxylin, and lamellar bone structures seen in normal bone tissue were not observed by polarized light microscope. They did not show the same staining tendency as normal bone in the PAM stain, so there was a difference between them in their maturity.
In this case, it was suggested that inflammation also seen in the specimen might be related to cyst-like appearance of the fibroma formation.