Peripheral granular cell odontogenic fibroma

Peripheral odontogenic fibroma is a rare lesion that arises on the gingiva and can clinically mimic a variety of reactive lesions, benign neoplasms, and metastases. We describe a symptomatic lesion arising on the mandibular gingiva of a 58-year-old female with no history of trauma or dental disease in the area. An excisional biopsy showed the lesional stroma to contain numerous polyhedral granular cells with occasional interspersed islands of inactive odontogenic epithelium. We believe this to represent the fourth case of peripheral granular cell odontogenic fibroma to be reported in detail in the literature.     

Peripheral odontogenic fibroma: a clinicopathologic study

The clinicopathologic features of 30 cases of peripheral odontogenic fibroma are reviewed. The age distribution is wide (11 to 76 years), and there is a slight predilection for males. The majority of the lesions (93%) occurred in blacks on the attached gingiva, and with equal frequency in the maxilla and mandible. Size varied between 1 and 3 cm in diameter. One case recurred after 14 months. Histologically, the lesions are nonencapsulated and poorly delineated. The amount of odontogenic epithelium varies considerably and consists usually of small islands or strands, although larger follicles are sometimes present. In one case the epithelial cells had a clear cytoplasm, whereas in another it was granular and eosinophilic. Origin from the surface oral mucosa can sometimes be seen. The connective tissue component is usually cellular, but collagenous, myxomatous, and mixed forms occur. Calcifications were present in 22 cases and consisted of tissue interpreted as either dentinoid, cementum, bone, or dystrophic calcific material.     

Peripheral odontogenic fibroma. Report of 5 cases

The peripheral odontogenic fibroma (WHO type) is a relatively rare, benign, unencapsulated, exophytic gingival mass of fibrous connective tissue. Odontogenic epithelium is found within the gingival mass, but usually appears to play a minor role when compared to the fibrous component. According to the present concept, cases reported in the literature under the terms "odontogenic gingival epithelial harmartoma" "hamartoma of the dental lamina" and "peripheral ameloblastic fibrodentinoma" are actually examples of peripheral odontogenic fibroma. Review of the literature revealed only 30 acceptable cases that fit the present concept of peripheral odontogenic fibroma. Because of the paucity of reported cases, the histomorphological spectrum and the clinical features of this lesion have not yet been fully established. This article presents five new cases of peripheral odontogenic fibroma. The connective tissue ranged from markedly cellular to relatively acellular well collagenized. Islands and strands of epithelium were present in all five cases: in four they were scanty and in one abundant. A matrix of mineralized material was present in four cases. The peripheral odontogenic fibroma must be differentiated histologically from peripheral ossifying fibroma, which is a reactive lesion, and from the peripheral ameloblastoma and the calcifying epithelial odontogenic tumour.     

Central odontogenic fibroma

An example of a central odontogenic fibroma is presented. This is a rare, benign neoplasm which affected the molar region of the left side of the mandible of a 63-year-old female Caucasian. Histologically, it consisted of fibroblast-like cells lying in a rather myxomatous delicate collagenous stroma. Few islands of odontogenic epithelium were also found. At the ultrastructural level, the tumour cells contained large numbers of fine filaments with focal densities similar to those described in smooth muscle cells. They also showed a moderately developed r ER. These features are consistent with cells referred to as myofibroblasts.     

Central odontogenic fibroma

The article presents a case of central odontogenic fibroma occurring in the maxilla. The literature is reviewed, in the belief that a discussion of the controversial issues surrounding this neoplasm, its treatment and follow-up information, is warranted, due to the small number of cases (13) of this tumor that have been recognised and reported up to the present.     

The peripheral odontogenic fibroma.

An extensive review of the English-language literature has produced only five undoubted cases of peripheral odontogenic fibroma. This article reports ten new cases. The age and sex of the patients and the distribution by site and histology of the lesions are compared with those of other cases of bifrous tumors and neoplasms of odontogenic origin. It is postulated that this lesion may be more closely related to the fibrous euplis than was previously realized. Both lesions show hyperplasia of the basal layer of the covering ipithelium into double strands resembling odontogenic epithelium. It is suggested that this hyperplasia may be related to induction of the covering epithelium by primitive ectomesenchymal remnants within the gingivae. Proliveration of odontogenic rests within the peripheral odontogenic frbroma may be related to the same stimulus.     

Granular cell peripheral odontogenic fibroma

A case of a peripheral odontogenic fibroma which contained aggregates of large granular cells is reported. These granular cells are similar to those previously described in the granular cell myoblastoma, congenital epulis and the granular cell ameloblastic fibroma. Deep extensions of the basal layer of overlying gingival epithelium, in double-strand fashion, are frequently observed in peripheral odontogenic fibromas. These strands closely resemble those seen in the tumor itself. On this basis, and as similar basal cell prolongations are seen in other jaw lesions, it is postulated that residual ectomesenchymal influence may be responsible for inducing the basal cell proliferations in a similar manner to that which occurs during early embryonic dental development. This, it is suggested, might possibly be the histogenesis of the odontogenic epithelial strands in the peripheral odontogenic fibroma.     

Central odontogenic fibroma current concepts

The author reviews current knowledge concerning the central odontogenic fibroma, which at present is incompletely understood, and reaches the following conclusions. 1) The separation of this lesion into simple and WHO types remains valid because they exhibit different histologic features. However, more care should be taken in rendering the diagnosis of the WHO type than in the past; unlike the simple type, it is a fibroblastic lesion. 2) Complex central odontogenic fibroma is a more appropriate term than the WHO type because the WHO does not use the latter term in its 1992 manual. 3) The microscopic distinction of simple odontogenic fibroma from desmoplastic fibroma remains difficult in some cases. 4) The granular cell odontogenic tumor, which has sometimes been referred to as a type of odontogenic fibroma, is a separate entity, although some simple odontogenic fibromas exhibit scattered granular cells. 5) The separation of lesions that have been reported recently as odontogenic fibromas with giant cell reactions from central giant cell granulomas that exhibit foci of odontogenic epithelium requires further study.     

Central granular cell odontogenic fibroma

First described in 1962, the so-called granular cell ameloblastic fibroma has been a rarely reported benign odontogenic tumor. On reviewing the literature, we have identified eight previously reported cases. All cases involved well-circumscribed radiolucencies in women who ranged in age from 53 to 65 years. Seven lesions occurred in the posterior body of the mandible, and one occurred in the premolar region of the maxilla. All lesions were treated with surgical excision, and no recurrences were identified during follow-up periods of 6 to 144 months. Two additional cases also appear to represent instances of this neoplasm, which bring the total number identified to ten. We describe the clinical, radiographic, and histopathologic features of two additional cases and suggest reasons the tumor should be referred to as central odontogenic fibroma, granular cell variant.     

Peripheral odontogenic fibroma (WHO type) of the newborn: a case report

AIM: The present paper reports a case of peripheral odontogenic fibroma (POF) (WHO type) in a newborn. The differential diagnosis and treatment were discussed. BACKGROUND: POF is well described in the literature, but this is the first report in a newborn. PATIENT: A 4-month-old female newborn was referred to our department because of an exophytic, sessile, firm, and well-delimited lesion on the right upper alveolar ridge. The covering mucosa was apparently normal. The lesion measuring 10 x 3 mm was present since birth. The clinical diagnosis of congenital granular cell tumour (congenital epulis) or dental lamina cyst of the newborn was made. A conservative excisional biopsy was performed under local anaesthesia, and the specimen was submitted to histopathological examination. RESULTS: The microscopic examination revealed a pattern of POF (WHO type). Normal primary incisors teeth eruption, and no signs of recurrence were noted on 16 months follow-up. CONCLUSION: Despite the rarity of POF in a newborn, this lesion should be included as a possible diagnosis to focal gingival growth.     

Peripheral ameloblastic fibroma

Peripheral ameloblastic fibroma is an exceedingly rare lesion. Only three reports could be found, two of which appeared in the Japanese literature. Here, we report a case of peripheral ameloblastic fibroma occurring in a 5-year-old girl. The diagnosis was made after careful microscopic examination, to exclude other lesions. The lesion was excised and has not recurred 1 year after removal.     

Peripheral ossifying fibroma

The peripheral ossifying fibroma (POF) is a common gingival growth usually arising from the interdental papilla. The anterior maxilla is the most common location of involvement. The etiology and pathogenesis of POF remains unknown. Some investigators consider it a neoplastic process, whereas others argue that it is a reactive process; in either case, the lesion is thought to arise from cells in the periodontal ligament. Trauma or local irritants, such as dental plaque, calculus, microorganisms, masticatory force, ill-fitting dentures, and poor quality restorations, have been implicated in the etiology of POF. The recommended treatment is the excisional biopsy; however, it can leave a defect if the procedure is not followed by a subepithelial connective tissue graft. The main objective of this article was to present a clinical case of excisional biopsy of a POF followed by a subepithelial connective tissue graft to correct the defect caused by the biopsy. The biopsy defect was satisfactorily repaired, and the lesion has not recurred after 6 years of follow-up.     

Comparison between the peripheral ossifying fibroma and peripheral odontogenic fibroma

This study presents previously unreported data on a series of 400 peripheral ossifying fibromas (POFs) and 13 peripheral odontogenic fibromas (PODFs). The differences between the two lesions are discussed, and comparisons are made with other reports in the literature. It is concluded that the lesions represent separate pathologic entities.     

Peripheral odontogenic keratocyst

The gingival cyst of the adult exhibits an epithelial lining that is essentially the same as the lateral periodontal cyst. Although the gingival cyst of the adult exhibits some morphologic variability, its lining is generally considered to be nonkeratinized. Nonetheless, rare cases of gingival cyst of the adult that exhibit a keratinized epithelial lining have been reported in the literature. There is now a growing tendency to consider this variant as a separate entity. This article describes six cases of gingival cysts that exhibit the histologic features of the odontogenic keratocyst. Evidence from this series suggests that the biologic behavior of this subset of gingival cysts is different from that of the generic gingival cyst of the adult and that the termperipheral odontogenic keratocyst more accurately describes this entity.