The Case of Peripheral Ossifying Fibroma

An 18-year-old female patients came to the OMFS department with complaint of discomfort on chewing. Oral examination revealed a pinkish-red colored lesion on buccal and lingual gingiva in the interdental area of mandibular central incisors. Lesion was soft in consistency and measured approximately 2 cm in diameter. Patient said that it's been there for two months.

Excisional biopsy was performed by the oral surgeon. 

Considering the gingival location, the top entities in our differential diagnosis were pyogenic granuloma, peripheral ossifying fibroma and peripheral giant cell granuloma.

Microscopic examination showed a nodule of mucosa surfaced by stratified squamous epithelium. The body of nodule was composed of benign proliferation of plump fibroblasts. Bone formation is identified in some portions. Based on this histopathological presentation, a diagnosis of peripheral ossifying fibroma was made.

Histological slide showing plump fibroblasts and calcifications

Peripheral Ossifying Fibroma:

The peripheral ossifying fibroma is a benign proliferation that occurs exclusively on the gingiva. It is seen more commonly in teenagers and young adults. It usually presents as a pedunculate or sessile nodular mass in the interdental region clinically. The color of the nodule ranges from red to pink depending on the degree of irritation.

Conservative surgical excision is the preferred form of management for this process. Despite their benign nature, these lesions have the ability to become pretty large. 

The Case of a Huge Mandibular Radiolucency

A 35-year-old patient came to the department with the complaint of pain and swelling in lower left region for the past one year. The swelling was smaller initially but had been gradually increasing in size. The rate of growth had accelerated in the past couple of months. The complaint of pain associated with this swelling was relatively recent. 

On oral examination an ulcerated lesion was noted on the lower left alveolar ridge  The swelling was tender on touching and firm on palpation. No palpable lymph nodes were identified during the extra oral examination. The patient's medical history was significant for a "back" problem. She was wheel chair bound for that purpose.

Clinical picture showing the ulcerated swelling on the left alveolar ridge extending to the buccal vestibule

A multilocular radiolucency was identified in the radiograph pushing the impacted third molar against the border of mandible. In some places a sclerotic margin could be identified at the margins of the radiolucency.

OPG showing the multilocular radiolucency in association with an impacted third molar

The surgeons performed an intraoral biopsy of the lesion from the alveolar ridge. The tissue was somewhat jelly-like in texture.

Biopsy specimen of the patient

The pathologist signed out the case as an odontogenic myxoma. Her report indicated that the sections showed a benign tumor with loose, myxomatous appearance. The cells were spindle shaped and fine collagen fibrils could be appreciated. 

The patient was scheduled for surgery but during her medical evaluation a murmur was identified and the anesthesiologist refused to put her under. We hope that that her medical issue is resolved so she can be treated for her disease.

Dr. K's Comments:

Odontogenic myxomas are rare, benign odontogenic tumors. They tend to favor the posterior mandibular area of young people, the average age is between 25 and 30. Smaller lesions may present as unilocular radiolucencies, while larger lesions, like ours are predominantly multilocular.

Some oral pathologists believe that odontogenic myxomas, odontogenic fibromyxomas and odontogenic fibromas are a spectrum of the same process. The classification varies depending on the amount of identifiable collagen. Since this process is exclusively found in the jaws, general pathologists usually end up lumping it in the fibromatosis category. Since both processes are benign and aggressive, I suppose even the incorrect diagnosis doesn't affect the prognosis. 

This process is managed through surgery. Since the lesion is not encapsulated, its cells infiltrate into the surrounding bone making definition of margins really difficult. Aggressive curettage following removal of the tumor is usually done to ensure complete removal. Periodic re-evaluation is also necessary to monitor for recurrences.