Fibrous cortical defect (nonossifying fibroma) of the mandibular ramus: report of 2 cases

Literature Review, Case Presentation and Management of Non-ossifying Fibroma of Right Angle of Mandible: More Than just a Cortical Defect!

Non-ossifying fibroma (NOF) of jaw bones are rare. While NOF is the most common benign bone tumor of long bones with pathognomonic radiological features and bear a tendency for self-regression, gnathic NOF appears to be comparatively larger in size and behave more aggressively. A 16 years old female patient reported with painless swelling of the right side of the face of 4 months duration. Radiographic analysis showed a unilocular radiolucent lesion of right angle of the mandible with ill-defined margins, cortical perforation and thinning of inferior border. The lesion was provisionally diagnosed as odontogenic keratocyst/unicystic ameloblastoma and incisional biopsy was performed. The histopathological features and immunohistochemical characteristics favored a diagnosis of NOF. The lesion was excised and reconstructed. The excised specimen confirmed the diagnosis. There are no signs of recurrence at 18 months follow-up. NOF should be considered in the differential diagnosis of uni-/multilocular radiolucencies of jaws particularly the posterior mandible.

Benign fibrohistiocytic jaw lesions: a 48-year clinicopathologic analysis and review of the literature

OBJECTIVE

Intra-osseous fibrohistiocytic lesions have long been reported in the literature; evidence suggests they represent a heterogeneous group of reactive and neoplastic processes. This study evaluated a series of gnathic fibrohistiocytic lesions to identify and categorize their clinical, radiographic and morphologic spectrum.

STUDY DESIGN

A retrospective case search over 48 years was conducted for maxillary and mandibular intra-bony fibrohistiocytic lesions. Diagnoses were confirmed and demographic, radiographic, clinical and follow-up data was analyzed.

RESULTS

Fifty cases met the inclusion criteria. Most cases (80%) were found in the second through fourth decades (mean, 29 years). The most common location (86%) was the posterior mandible. Radiographic presentations varied, but a few patterns emerged, including a distinctive mottled, honeycomb type with punctate lucencies. All cases demonstrated fibrous components admixed with variable histiocytes. Eight cases (16%) were histiocyte-rich with dominant sheets of xanthoma cells. Immunohistochemical staining revealed strong CD68 and CD163 expression, along with variable smooth muscle actin staining. The vast majority (92%) of cases were treated conservatively. Available follow-up showed lesional stability in 17 cases (average, 85 months) with 2 recurrences (24 months each) and no evidence of malignant transformation.

CONCLUSIONS

This study is the largest to date of fibrohistiocytic gnathic lesions, revealing distinctive radiographic and histologic findings and characteristic clinical and immunophenotypic features. Available evidence suggests that most of these are indolent, slow-growing lesions amenable to conservative therapy.

Intraosseous solitary myofibroma of the orbit in an adolescent woman

A 16-year-old woman presented with a painless, progressive, hard swelling in the left inferolateral orbital wall for the past 1 year. There was no diminution of vision or limitation of ocular motility. Imaging revealed an intraosseous, well-defined, expansile, soft tissue lesion in the inferolateral wall of the left orbit. A left anterior orbitotomy with complete surgical excision was performed. Histopathological evaluation of the specimen revealed fascicular pattern of spindle cells with a rich network of slit-like, branching blood vessels. Tumour cells exhibited smooth muscle actin and vimentin positivity but were negative for CD-34 and STAT-6. In absence of any systemic manifestation, a diagnosis of intraosseous solitary orbital myofibroma was made. The case highlights the importance of integrating clinical, radiological and histopathological features in overcoming the diagnostic challenge of differentiating myofibroma from other mesenchymal neoplasms. It also brings forth the importance of complete resection and curettage to prevent recurrence.

Nonossifying fibroma of the rib resected by video-assisted thoracoscopic surgery with preservation of periosteum

Nonossifying fibromas are not uncommon, but those described in the rib are unique. We report the case of a 15-year-old patient with symptoms of chest wall pain for 5 days who underwent a video-assisted thoracoscopic rib resection for a 2.5-cm rib mass. Unexpectedly, pathological results revealed a nonossifying fibroma of the rib. The results showed excellent cosmesis and new bone formation because of the preservation of the overlying periosteum.

The non-ossifying fibroma: a case report and review of the literature

The non-ossifying fibroma (NOF) is a benign, non-neoplastic lesion most commonly seen in the metaphyses of the long bones in children. While rare, the NOF has been reported in the mandible. The NOF in the extra-gnathic skeleton has a characteristic radiographic appearance, is typically asymptomatic and has a variable histologic make-up. Correlation of the radiographic appearance, clinical presentation and histopathology allows for differentiation of the NOF from odontogenic and non-odontogenic cysts and tumors. We report a new case of this interesting entity and review the radiographic, clinical and histologic features of the gnathic NOF reported in the literature. A thorough search of the English language literature returned a total of 19 cases of NOF involving the gnathic bones.

A multilocular radiolucency with spindle cell proliferation in a case of ossifying fibroma: a potential pitfall

Ossifying fibroma (OF) is a benign tumour characterized by cementum or bone formation accompanied by a fibrocellular stroma. The diagnosis of OF may be apparent when the histological features are supported by clinical and radiological information. In this report, an OF with predominantly spindle cell proliferation and purely radiolucent, multilocular lesion in a middle-aged woman is presented.