Clinicopathologic Correlation: Firm Mass on the Lateral Aspect of the Posterior Maxilla
Darin T. Johnston, James J. Closmann, Pallavi Parashar, Thomas J. Borris
A 40-year-old female was referred to the Oral Surgery clinic with severe pain in the maxillary left quadrant, which presented for several weeks. On radiographic examination, the patient was noted to have a large carious lesion on tooth #15 and teeth #15 and #16 were both mobile and extremely tender. Of note, the patient was observed to have a large, approximately 2 cm in greatest dimension, pinkish mucosal covered mass on the buccal aspect of her posterior maxilla over the area of teeth #15 and #16. The patient stated it had been there for many years and was told it was bone by her previous dentist. The mass was firm, non-tender, showed very slight mobility and no bleeding. A differential diagnosis of the lesion was formulated and included: maxillary exostosis, peripheral ossifying fibroma, peripheral fibroma, peripheral giant cell granuloma, and possibly a peripheral manifestation of an odontogenic tumor.
Using local anesthesia an excisional biopsy was performed on the lateral maxillary mass using a #15 blade. Care was taken to remove the lesion with a cuff of healthy appearing tissue at the base.
The biopsy sample represented a mucosal nodule covered by intact keratinizing squamous epithelium was supported by connective tissue, which was rich in collagen. Within the collagen, there was evidence of ossifications representing a mineralized product such as bone. Based on these histologic findings, a diagnosis of peripheral ossifying fibroma was rendered. No further treatment for the lesion was scheduled.
Peripheral ossifying fibroma (POF) is a reactive non-neoplastic lesion, and is not a soft tissue version of the central ossifying fibroma. It presents on the gingiva as a painless, firm, localized growth with either a sessile or pedunculated base that does not blanch when palpated. The surface can be similar to adjacent unaffected gingiva or red, and can be ulcerated. The interdental papilla is the most common site. The lesion occurs more commonly in women, and occurs almost equally on the maxilla or mandible. Similar to other gingival swellings, POF most commonly develops in reaction to irritation. POF originates from the periodontal ligament and/or periosteum that is capable of producing the bone, cementum, and fibrous tissue. To minimize recurrence, treatment is complete excision and possible extraction of involved teeth.