This case series describes the clinical, imaging, and histological features of 27 lesions diagnosed as a benign fibrous mass not previously described in veterinary literature. The authors propose the name gingival mucoperiosteal fibroma (GMPF) to describe these fibrous lesions found in dogs. Histologically, GMPF is characterized by a lack of odontogenic tissue and various degrees of ossification. GMPFs affect adult dogs with an average age of 95 months (range 24-156 months) and appear as expansile growths with superficial appearance matching the surrounding gingiva. The mandibular incisive region is the most commonly affected region (n = 13) and most cases have some level of bone proliferation radiographically (n = 14). Histological examination of the masses shows poorly cellular fibrous tissue with thick interwoven collagen fibers. Bony invasion by the mass was not noted, though histological proliferation of bone was seen in 17 lesions. Surgical resection was curative in all cases when performed, and no recurrence was seen at time of follow-up. Fibrous lesions of the oral cavity in dogs are poorly defined and categorized, though numerous lesions have been described in both human and veterinary literature.

BACKGROUND: Granular Cell Odontogenic Fibroma (GCOF) is a rare odontogenic neoplasm reported over time with different names. The purpose of this study is to review all available data on the GCOF in the scientific literature, with a summary of all reported cases and a report of a new case.
METHODS: This review was conducted following the PRISMA guidelines. An electronic search was performed up to November 2022.
RESULTS: Thirty-nine studies reporting fifty-three cases were included. GCOF is a rare neoplasm among the odontogenic tumors, with a higher prevalence in women of the middle-aged and white population. This lesion occurs mostly on the posterior region of the mandible. Furthermore, based on clinical, radiographic, and histopathologic features, conservative treatment was the most reported choice with recurrence reported in two cases.
CONCLUSIONS: GCOF remains controversial due to the still unsolved histogenesis.

BACKGROUND: Odontogenic fibroma (OF) is a rare benign tumor of mesenchymal odontogenic tissue with variable global incidence. Two variants comprising extraosseous /peripheral (POF) and intraosseous /central (COF) have been identified based on the anatomical origin of the tumor. OF isslow growing, and often asymptomatic with characteristic radiographic appearance of a unilocular or multilocular cyst frequently associated with unerupted or displaced teeth while histologically, varying amount of inactive odontogenic epithelium embedded in a mature relatively dense collagenous stroma is diagnostic. The absence of odontogenic epithelium does not exclude the diagnosis of odontogenic fibroma.
METHODS: A 15 months old female presented with 3 months history of left lower jaw swelling which showed aggressive growth following incisional biopsy. Parents said lesion was noticed for the first time as pinpoint on the submandibular area and was too small to warrant any worries. Initial radiograph revealed absence of bony involvement but the second showed evidence of bony involvement. An impression of soft tissue sarcoma was made and incisional biopsy was sent for pathological diagnosis which revealed peripheral odontogenic fibroma. The rapidity of growth following incisional biopsy bellied a benign lesion.
CONCLUSIONS: An aggressive odontogenic fibroma with multifocal points in a 15months old girl.
BACKGROUND: Le fibrome odontogène (FO) est une tumeur bénigne rare du tissu odontogène mésenchymateu dont l’incidence globale est variable. Deux variantes comprenant des fibromes extra-osseux /périphérique (POF) et intra-osseuse / centrale (COF) ont été identifiés en fonction de l’origine anatomique de la tumeur. La POF est à croissance lente, et souvent asymptomatique avec l’apparence radiographique caractéristique d’un kyste uniloculaire ou multiloculaire fréquemment associé à des dents non érigées ou déplacées alors que histologiquement, une quantité variable d’épithélium inactif noyé dans un stroma collagène mature relativement dense est le diagnostic. L’absence d’épithélium odontogène n’exclut pas le diagnostic de fibrome odontogène.
UNASSIGNED: Une femme de 15 mois a présenté un gonflement de la mâchoire inférieure gauche depuis 3 mois de gonflement de la mâchoire inférieure gauche qui a montré une croissance agressive après une biopsie incisionnelle. Les parents ont déclaré que la lésion avait été remarquée pour la première fois sur forme de point d’épingle dans la zone submandibulaire et était trop petite pour justifier une quelconque inquiétude. La radiographie initiale a révélé l’absence d’atteinte osseuse mais la seconde a montré des signes d’atteinte osseuse. Une impression de sarcome des tissus mous et une biopsie incisionnelle a été envoyée pour un diagnostic pathologique qui a révélé un fibrome odontogène périphérique. La rapidité de la croissance après la biopsie incisionnelle a fait croire à une lésion bénigne.
CONCLUSIONS: Un fibrome odontogène agressif avec des points multifocaux chez une jeune fille de 15 mois.
UNASSIGNED: Fibrome odontogène, Périphérique, Central, Agressif.