Ossifying fibromas of the jaw bone: 20 cases

Association of hyperparathyroidism and benign fibro-osseous jaw tumors: a 25-year retrospective study at Mayo Clinic

PURPOSE

The purpose of this study is to evaluate the association between hyperparathyroidism (PHPT), parathyroid hormone levels, and calcium levels in patients diagnosed with benign fibro-osseous lesions such as fibrous dysplasia (FD), ossifying fibroma (OF), central giant cell granulomas (GCG).

METHODS

This is a retrospective, single-center study from a sample of patients who underwent surgical treatment of FD, OF, and GCG at Mayo Clinic between 1996 and 2021. Patient demographics, history of PHPT, histopathological diagnosis, and relevant laboratory values such as parathyroid hormone (PTH), serum calcium, vitamin D, and alkaline phosphatase were collected.

RESULTS

Of the patients diagnosed with FD (n = 64), OF (n = 24), and GCG (n = 5), a diagnosis of PHPT was found in 2 patients (3.1%), 1 patient (4.2%), and 0 patients (0%), respectively. Elevated PTH levels (>65 pg/mL) were observed in 3 patients (4.7%) with FD, 1 patient (4.2%) with OF, and 1 patient (20%) with GCG. Mean (standard deviation) calcium levels were 9.3 (0.6) mg/dL in the FD group, 9.4 (0.5) mg/dL in the OF group, and 9.3 (0.6) mg/dL in the GCG group. Patients with fibro-osseous jaw tumors including FD, OF, and GCG may have increased risk of PHPT compared to the general population.

CONCLUSION

Patients with benign jaw tumors including FD, OF, and GCG may have increased risk of PHPT compared to the general population. Surgeons treating these benign tumors need to be cognizant of these findings, obtain appropriate laboratory studies, and incorporate multidisciplinary care including endocrinologists, endocrine surgeons, and maxillofacial surgeons.

CT-based radiomics analysis of different machine learning models for differentiating gnathic fibrous dysplasia and ossifying fibroma

OBJECTIVE

In this study, our aim was to develop and validate the effectiveness of diverse radiomic models for distinguishing between gnathic fibrous dysplasia (FD) and ossifying fibroma (OF) before surgery.

MATERIALS AND METHODS

We enrolled 220 patients with confirmed FD or OF. We extracted radiomic features from nonenhanced CT images. Following dimensionality reduction and feature selection, we constructed radiomic models using logistic regression, support vector machine, random forest, light gradient boosting machine, and eXtreme gradient boosting. We then identified the best radiomic model using receiver operating characteristic (ROC) curve analysis. After combining radiomics features with clinical features, we developed a comprehensive model. ROC curve and decision curve analysis (DCA) demonstrated the models' robustness and clinical value.

RESULTS

We extracted 1834 radiomic features from CT images, reduced them to eight valuable features, and achieved high predictive efficiency, with area under curves (AUC) exceeding 0.95 for all the models. Ultimately, our combined model, which integrates radiomic and clinical data, displayed superior discriminatory ability (AUC: training cohort 0.970; test cohort 0.967). DCA highlighted its optimal clinical efficacy.

CONCLUSION

Our combined model effectively differentiates between FD and OF, offering a noninvasive and efficient approach to clinical decision-making.

Ossifying fibroma of the maxilla: A case report with literature review

Ossifying fibroma is a benign fibro-osseous lesion arising from the periodontal ligament cells. The lesion may progressively enlarge with the mass affecting the mandible or maxilla, resulting in facial deformities and tooth displacement despite its benign nature. Here, we presented a case of an 18-year-old female with ossifying fibroma in the maxilla extending to the maxillary sinus, infraorbital area, and skull base, resulting in considerable facial asymmetry. Since the primary treatment of ossifying fibroma is surgical resection, it is essential to determine the areas where the lesion has expanded, where a 3-dimensional computed tomography scan could play a critical role in providing such information. A complete surgical excision and histopathologic examination in treating this patient are crucial, made possible by a meticulous preoperative radio imaging technique.

A family case report of parathyroid carcinoma associated with CDC73 mutation in hyperparathyroidism-jaw tumor syndrome

Background

Hereditary primary hyperparathyroidism (PHPT) accounts for 5-10% of all PHPT cases, necessitating genetic testing for diagnosis and management. Among these, hyperparathyroidism-jaw tumor syndrome (HPT-JT) is an autosomal dominant disorder caused by CDC73 mutations with variable clinical presentations and incomplete symptoms.

Case summary

The proband, diagnosed with PHPT, underwent parathyroidectomy at the age of 41 with pathological examination of parathyroid carcinoma (PC). Hereditary PHPT was initially suspected due to the early-onset PHPT and family history. Genetic testing identified a heterozygous CDC73 mutation, NM_024529.4: c. 687_688delAG (p. Arg229Serfs*37). Even in the absence of jaw tumors, the diagnosis of HPT-JT was confirmed based on the discovery of renal cysts. A secondary thyroidectomy was performed to reduce the risk of recurrence.

Conclusion

Genetic testing is strongly recommended in cases of early-onset PHPT, family history, jaw tumors, renal and uterine involvement, atypical parathyroid tumors, and PC. This testing provides valuable information for personalized management, and counseling is available for affected families.

Ossifying Fibroma of Mandible - A Case Report

INTRODUCTION

Ossifying fibromas are rare, non-aggressive benign tumours of the bone, commonly involving the posterior mandible in middle-aged individuals with a female predilection.

FINDINGS

Clinical manifestations include asymptomatic expansion of the mandible with infrequent maxillary lesions, pain, malocclusion, and compromised quality of life including aesthetic perception. Owing to multiplicity of features, tendency of recurrence, and possibility of malignant transformation, the diagnosis, treatment, and post-operative management of ossifying fibroma are always a challenge.

TAKEAWAY LESSONS

Study aims to report a clinical case of extensive swelling involving the coronoid process and condyle on the right side to crossing the mid-line of the mandible with compromised functions and aesthetics. The article describes the clinical, histopathological, and radiological features of the case. The possible treatment and challenges encountered are discussed.

Molecular and Clinical Spectrum of Primary Hyperparathyroidism

Recent data suggest an increase in the overall incidence of parathyroid disorders, with primary hyperparathyroidism (PHPT) being the most prevalent parathyroid disorder. PHPT is associated with morbidities (fractures, kidney stones, chronic kidney disease) and increased risk of death. The symptoms of PHPT can be nonspecific, potentially delaying the diagnosis. Approximately 15% of patients with PHPT have an underlying heritable form of PHPT that may be associated with extraparathyroidal manifestations, requiring active surveillance for these manifestations as seen in multiple endocrine neoplasia type 1 and 2A. Genetic testing for heritable forms should be offered to patients with multiglandular disease, recurrent PHPT, young onset PHPT (age ≤40 years), and those with a family history of parathyroid tumors. However, the underlying genetic cause for the majority of patients with heritable forms of PHPT remains unknown. Distinction between sporadic and heritable forms of PHPT is useful in surgical planning for parathyroidectomy and has implications for the family. The genes currently known to be associated with heritable forms of PHPT account for approximately half of sporadic parathyroid tumors. But the genetic cause in approximately half of the sporadic parathyroid tumors remains unknown. Furthermore, there is no systemic therapy for parathyroid carcinoma, a rare but potentially fatal cause of PHPT. Improved understanding of the molecular characteristics of parathyroid tumors will allow us to identify biomarkers for diagnosis and novel targets for therapy.

Spontaneous Regression of Ossifying Fibroma in the Oral and Maxillofacial Region: A Rare Case With 4-Year Follow-Up

The case presented in this study is a rare instance of an ossifying fibroma (OF), a type of benign fibro-osseous lesions, spontaneously regressed without surgical intervention. A 9-year-old boy with an intraosseous lesion in the left maxilla was diagnosed as OF. The surgeon suggested surgical excision, but due to personal reasons, the patient and his parents deferred the surgery and opted for regular follow-up. During a 4-year follow-up, the surgeon found that the lesion had significantly decreased in size and the facial deformity had remitted. At the latest follow-up, the deformity of his left face became almost unnoticeable, and the lesion seemed to be subtle on cone-beam computed tomography images. This case highlights the possibility of spontaneous regression of OF. This phenomenon may occur due to the teeth eruption, which can lead to the formation of periodontal ligaments and engage the regression of OF.

Treatment of an ossifying fibroma of the mandible with endodontic microsurgery and grafting with a biphasic calcium sulfate material: a case report

A significant percentage of lesions of endodontic origin require surgical management due to the possible diagnosis of odontogenic cysts and tumors in the maxilla and mandible. Ossifying fibroma is a benign fibro-osseous lesion that typically presents as a painless, slow-growing, and expansile lesion that appears as a well-demarcated lesion with a variable degree of internal calcification on radiography. Treatment results in a large osseous defect, utilization of a graft to fill the void accelerates healing and prevents complications that may result from failure to fill by the host response.

CASE PRESENTATION

Following endodontic surgery placement of osseous graft material via Guided Tissue Regeneration to fill the defect aids to accelerate fill of the defect on a healthy 26-year-old female patient. A case discussing the one-step treatment of an ossifying fibroma of the anterior part of the mandible following endodontic microsurgery with associated retrograde fill of the apex, then site grating with biphasic calcium sulfate (Bond Apatite®) used in regeneration of the osseous defect related to the lesion and resulting surgery.

CLINICAL DISCUSSION

Histologically, the ossifying fibroma is dominated by connective tissue containing cell rich areas with a few fragments of fibrosis. Moreover, in the connective tissue numerous small fragments of spongy and compact bone with areas of partial necrosis present and a significant number of inflammatory cells are observed. Surgical removal of the cyst with thorough curettage of the osseous walls and grafting of the defect provides predictable healing and the desired clinical results sought. Utilization of the biphasic calcium sulfate graft material allows the elimination of the need to overlay the area with a membrane before the flap due to its hard set and the prevention of soft tissue ingrowth into the graft material during the healing phase. Additionally, the hard set of the material allows tenting of the area to maintain the desired volume and ridge contour. Conversion of the graft material depending on the volume placed to host bone occurs over a 3-6 month period.

CONCLUSION

The case report presented, as well as the authors experience mimics the literature on biphasic calcium sulfate in its use as an osseous graft material and is an effective method for the repair of osseous defects that result from the removal of tumors and cysts of the maxilla and mandible. Treatment of an ossifying fibroma is an ideal application of the use of this biphasic calcium sulfate material allowing tenting of the surgical site over the defect created after cyst removal without the need for resorbable collagen membranes. This simplifies its use and decreases material costs that may hamper patient acceptance of treatment without a decrease in expected clinical results.

A Painless Bump: A Case Report of Cemento-Ossifying Fibroma of the Anterior Maxilla

Cemento-ossifying fibroma (COF) is a benign odontogenic neoplasm. It is considered an ossifying fibroma with traces of interspersed cementum fragments. Here we present a case report of the occurrence of COF in the maxillary anterior region of an elderly woman. A 61-year-old female reported with a painless, progressive, slow-growing swelling on the upper front jaw region for the past five years. A single, localized, swelling on the anterior region of the maxilla which was non-tender and bony hard in consistency. Radiological examination consisting of orthopantomagram (OPG) and cone-beam computed tomography (CBCT) revealed increased thickness of bone over frontal, parietal and maxilla with alteration of trabecular pattern - cotton wool/ground glass. Serum alkaline phosphatase level was found to be 865 U/l, however, serum calcium level and other routine blood investigations (hemogram) were within normal limits. The above radiological and laboratory findings are more in favour of primary bone pathology and with a biopsy later correlating with histopathological findings; it was diagnosed as COF. Under conscious sedation, surgical excision of the bony mass was done along with extraction of associated teeth. The patient is currently on regular follow-up and planning for a dental prosthesis is in progress.

Single stage maxillofacial reconstruction combined radical surgery for managing juvenile ossifying fibroma: A case report

Ossifying fibroma (OF) in craniofacial is a rare disease, benign, locally aggressive fibro-osseous tumor. The 2017 World Health Organization classifications divided OF into two types: OF of odontogenic origin and juvenile ossifying fibroma (JOF). Determining the right surgical treatment to reduce the postoperative recurrence rate is incredibly challenging. The author reports two cases of paranasal sinuses with disease onset progressed from pre-pubertal age. The first case is an example of a recurrent case after undergoing conservative surgery, and the second is a new one. All cases underwent radical surgery with subtotal maxillectomy and reconstructive surgery in one stage. After observing all patients until one year, there was no sign of recurrence through clinical and endoscopic examination. There are two types of surgery that compare in this case report: conservative surgery and radical surgery. Conservative surgical procedures include curettage, enucleation, or peripheral osteotomies. Several studies have shown high recurrence levels in OF patients when curettage or enucleation is performed; residue caused by incomplete excision is the most common reason that is easily caused by conservative surgery. Radical surgery such as open maxillectomy is a promising approach for degrading the level of recurrence. JOF, especially trabecular juvenile ossifying fibroma, shows a high recurrence percentage comparing other types. The first-choice management for treating OF was the surgical approach. Types of surgery depend on the disease's aggressiveness and morbidity. Radical surgery was proven better at decreasing recurrence level than conservative surgery.

Rare duplication of the CDC73 gene and atypical hyperparathyroidism-jaw tumor syndrome: A case report and review of the literature

BACKGROUND

Hyperparathyroidism jaw-tumor syndrome (HPT-JT) is the rarest familial cause of primary hyperparathyroidism, with an incidence <1/1000000, caused by a pathogenic variant in the CDC73 (or HRPT2) gene that encodes parafibromin, a protein involved in many cellular mechanisms. Patients with HPT-JT have a 15-20% of risk of developing parathyroid carcinoma, whereas it accounts for only 1% of all cases of primary hyperparathyroidism. Patients also develop jaw tumors in 30% of cases, kidney abnormalities in 15% of cases, and uterine tumors in 50% of patients.

CASE REPORT

Here are report two atypical cases of HPT-JT with variable expressivity in the same family. In front of an isolated primary hyperparathyroidism at 28 years of age of incidental discovery following a weight gain, the propositus benefited a first-line panel by Next-Generation Sequencing of the genes involved in familial hyperparathyroidism: CaSR, CDC73, MEN1, and RET. Genetic testing revealed the presence of a pathogenic germline variation CDC73: c.687_688dup; p.Val230Glufs*28, found only in nine families in the literature and allowing the diagnosis of HPT-JT. Given a history of primary hyperparathyroidism at 52 years and adenomyosis, the patient's mother also underwent a genetic analysis that found her daughter's variation and established her inherited trait.

CONCLUSION

In view of the clinical and genotypic heterogeneity, we confirm the interest of using an extended gene panel for the diagnosis of familial primary hyperparathyroidism. CDC73 variations could be more frequent than described in the literature. The association of primary hyperparathyroidism with uterine involvement could be a new indication for analysis.

A Clinical, Radiological and Histopathological Review of 74 Ossifying Fibromas

BACKGROUND

Ossifying fibroma (OF) is a fibro-osseous lesion of the jaws and craniofacial bones. Accurate diagnosis can be challenging due to significant overlap of clinicopathological features. This study aimed to evaluate the clinical, radiological and histological features that can aid in diagnosis and identify characteristics that allow categorisation into the three subtypes: juvenile trabecular, psammomatoid and cemento-ossifying OF.

METHODS

A total of 74 cases of OF were systematically reviewed for their principle features. Of these, 46 cases were evaluated for their radiographic features including size, location and relationship to the teeth. Histological assessment and stereological point counting were performed in 69 cases to assess the pattern, type and proportion of calcification, the nature of the stroma, the border of the lesion and the presence of secondary changes. Fisher's exact test and Chi-squared tests were used to determine associations between clinicopathological parameters and maxillary, mandibular, odontogenic, non-odontogenic and psammomatoid or trabecular lesions.

RESULTS

OF showed a female predilection (F: M; 2:1) and a slight bimodal age distribution with peaks in the second (23%) and fourth decades (27%) (Mean age: 32.4 years). 83% of cases presented as an intra-oral swelling, with the mandible being the most common site (73%). Histologically, a range of morphological patterns were seen, with 50% of cases showing mixed trabecular and psammomatoid features. However, there were no significant differences between the variants of OF in terms of age, gender or histological features.

CONCLUSION

Histological features of OF cannot be used to differentiate between the subtypes.

Tru-cut needle biopsy: A novel approach in the diagnosis of solid oral pathologies

Nowadays, new biopsy techniques such as fine and wide needles are now employed instead of invasive biopsy techniques. Compared to open biopsy, true-cut needle biopsy has a number of advantages. It's quick and simple to do, can be done in an outpatient department, avoids incisions into previously irradiated skin, and has few risks. In order to examine malignant and benign tumours, there had been a debate in the past century on the utilisation and efficiency of tru-cut biopsy over Fine needle aspiration cytology (FNAC) and surgical biopsy in solid tumours. A non-odontogenic tumour that occurs in jaws, also classified as a fibro-osseous lesion of the jaw, is Cemento-Ossifying Fibroma. Clinically, these lesions occur as gradually growing, reaching an enormous size if not treated. In this article, a case of cemento-ossifying fibroma noticed in the maxilla with facial swelling is discussed and the diagnosis was done using a tru-cut needle biopsy.

Ossifying Fibroma in the Maxilla and Mandible: A Case Report With a Brief Literature Review

Fibro-osseous lesions in the jaw bones include fibrous dysplasia, ossifying fibroma (OF), cemento-ossifying fibroma, florid osseous dysplasia, and focal osseous dysplasia. OF is the most common fibro-osseous tumor that presents as a slow-growing well-encapsulated benign neoplasm composed of varying amounts of bone or cement-like tissue in a fibrous stroma well-demarcated from the adjacent normal bone. OF is most common in the jaw bones, with a predilection for the mandible. OF usually occur as solitary lesions and rarely as multiple lesions in a patient. We present clinical and radiologic features, histopathology, and surgical management of a rare case with large synchronous OFs in the mandible and maxilla and a brief review of the literature.

Complete Spontaneous Bone Regeneration following Surgical Enucleation of a Mandibular Cemento-Ossifying Fibroma

Background

Cemento-ossifying fibroma (COF) is a type of benign fibro-osseous tumor that mainly occurs in the maxillofacial region. Bone reconstruction after the surgery is often performed with bone transplantation. However, the present case report describes the accurate diagnosis and successful surgical resection of a COF with periosteum preservation, after which the defect was completely and spontaneously filled with the newly formed bone through a natural process. Case Presentation. A 32-year-old Iranian female patient presented with a history of gradual development of painful swelling, spontaneous pain, and lower lip and chin hypoesthesia in the lower third of the left side of her face. The dome-shaped swelling was tender. The patient was suffering from renal infection and urethral prolapse and was taking folic acid. She also mentioned a positive family history of similar swellings in her mother and uncle. Intraoral examination indicated a lesion in buccal and lingual vestibules extending from the first premolar to the third molar teeth. It had a firm consistency, and the covering mucosa was normal in terms of color and texture. The aspiration test was negative. The lesion had caused severe mobility of the second premolar and first and second molar teeth. Panoramic radiography revealed an extensive well-defined unilocular radiolucency. Significant knife-edge resorption of the first and second molar roots at the involved site and thinning of the alveolar crest and inferior border of the mandible were also clear. Cone-beam computed tomography showed severe expansion in the buccal and moderate expansion in the lingual aspect, causing thinning of both the buccal and lingual cortical plates. Histopathological analysis revealed neoplastic tissue mixed with fibrous connective tissue and several round and oval-shaped calcification foci. Immunohistochemical analysis confirmed the final diagnosis (COF) with the presence of SMA-8. The lesion was removed by enucleation and curettage, while the periosteum was carefully preserved. Fixation with screw and plate was also performed.

Conclusions

Correct diagnosis of COF and precise implementation of the periosteal osteogenesis technique, in this case, resulted in entirely and spontaneously bone regeneration, which was a rare and favorable outcome with minimum cost and complications for the patient.

Aggressive juvenile ossifying fibroma of the ethmoid sinus with orbital and intracranial extension: A case report

BACKGROUND

Juvenile ossifying fibroma is a rare benign destructive lesion of nose and paranasal sinuses. It occurs in the craniofacial bones of children below 15 years of age. It is usually discovered in the mandible and maxilla and rarely in the paranasal sinuses.

CASE PRESENTATION

We present a case of a 15-year-old girl with extensive right ethmoid sinus juvenile ossifying fibroma with intracranial and orbital involvement that was managed endoscopically at our center followed by lateral rhinotomy and frontal craniotomy with reconstruction due to the aggressive nature and recurrence of the disease. Patient was followed up post operatively for 3 years and was found free of symptoms ever since.

CONCLUSION

In this case report we present our experience in managing this aggressive recurrent disease of juvenile ossifying fibroma which requires multiple endoscopic and open surgical procedures. Such pathology needs a close and long follow up due to the aggressive nature of this disease.

OUP accepted manuscript

We present an interesting case of a young male with incidental finding of a mandibular ossifying fibroma. The patient sustained direct trauma to the mandible which prompted a computer tomography (CT) scan evaluation of the facial bones. The CT scan showed bilateral mandibular fractures with one of the fractures extending through an incidental finding of a 2.3 cm mandibular parasymphyseal lesion. The patient was previously asymptomatic without dental pain, jaw pain or swelling. This case is unique in the fact that the patient has an inherently rare tumor, was asymptomatic prior to his injury, demographically young for the presentation of this size tumor, and highlights the importance of a through trauma workup.

Endoscopic Resection of a Massive Ossifying Fibroma in the Sinonasal Cavity

ABSTRACT

An ossifying fibroma (OF) is a type of benign fibro-osteoma that rarely involves the sinonasal cavity. Recent developments in endoscopic sinus surgery allow the removal of large benign tumors from the nasal cavity and sinuses. Here, the athors report the case of a 48-year-old female who underwent endoscopic sinus surgery under general anesthesia to completely remove a large OF involving the sphenoid sinus and nasal cavity. No recurrence was noted during the recent 3-year follow-up. Endoscopic resection of OFs is an excellent choice for very experienced surgeons, affording the advantages of direct observation as well as visual enhancement and magnification, thus reducing intra- and post-operative morbidity.

Copy number alteration profiling facilitates differential diagnosis between ossifying fibroma and fibrous dysplasia of the jaws

Ossifying fibroma (OF) and fibrous dysplasia (FD) are two fibro-osseous lesions with overlapping clinicopathological features, making diagnosis challenging. In this study, we applied a whole-genome shallow sequencing approach to facilitate differential diagnosis via precise profiling of copy number alterations (CNAs) using minute amounts of DNA extracted from morphologically correlated microdissected tissue samples. Freshly frozen tissue specimens from OF (n = 29) and FD (n = 28) patients were obtained for analysis. Lesion fibrous tissues and surrounding normal tissues were obtained by laser capture microdissection (LCM), with ~30–50 cells (5 000–10 000 µm²) per sample. We found that the rate of recurrent CNAs in OF cases was much higher (44.8%, 13 of 29) than that in FD cases (3.6%, 1 of 28). Sixty-nine percent (9 of 13) of the CNA-containing OF cases involved segmental amplifications and deletions on Chrs 7 and 12. We also identified eight CNA-associated genes (HILPDA, CALD1, C1GALT1, MICALL2, PHF14, AIMP2, MDM2, and CDK4) with amplified expression, which was consistent with the copy number changes. We further confirmed a jaw lesion with a previous uncertain diagnosis due to its ambiguous morphological features and the absence of GNAS mutation as OF based on the typical Chr 12 amplification pattern in its CNA profile. Moreover, analysis of a set of longitudinal samples collected from an individual with a cellular lesion in suspicion of OF at the first surgery, recurrence and the latest malignant transformation revealed identical CNA patterns at the three time points, suggesting that copy number profiling can be used as an important tool to identify borderline lesions or lesions with malignant potential. Overall, CNA profiling of fibro-osseous lesions can greatly improve differential diagnosis between OF and FD and help predict disease progression.

Ossifying Fibromas of the Head and Neck Region: A Clinicopathological Study of 45 Cases

Ossifying fibromas of the head and neck region are classified as cemento-ossifying fibroma (COF) (odontogenic origin), and two types of juvenile ossifying fibromas: juvenile trabecular ossifying fibroma (JTOF), and juvenile psammomatous ossifying fibroma (JPOF). The potential for recurrence in JTOF and JPOF and the discovery of newer molecular signatures necessitates accurate histological classification. Over 12 years (2005-2017), a total of 45 patients with 51 tumours were retrieved and reviewed for clinic-pathological features from the archives of a tertiary care oncology centre. Of 45 cases, COF, JTOF and JPOF comprised 13 (28.9%), 11 (24.4%) and 18 (40%) cases respectively. Three cases were unclassifiable. M: F ratio was 1:3.3, 1.1:1, 2:1 for COF, JTOF and JPOF respectively with an age range of 6-66 years (mean: 24.6, median; 18.1 years). The most common site for COF was mandible, for JTOF was maxilla, and for JPOF was ethmoid sinus. One case of mixed JTOF and JPOF histology was seen. Aneurysmal bone cyst-like areas were seen in 26.6% of cases, most commonly in JPOF. Follow up was available in 23 cases, and ranged from 4 to 207 months. Three cases of JPOF had a recurrence and one patient with JTOF had residual disease after surgery. One case of COF demonstrated increased parathyroid hormone levels. COF, JTOF, and JPOF are clinically, radiologically and histologically distinct entities. Surgical resection is the mainstay of treatment. JPOF has a higher incidence of recurrence as compared to JTOF and COF and hence needs a more aggressive follow-up.

The Unforeseen Diagnosis: Hyperparathyroidism-Jaw Tumour Syndrome Case Report and Review of the Literature

Hypercalcaemia and its systemic sequelae are a relatively common finding amongst patients in the field of endocrinology. Primary hyperparathyroidism, a frequent cause of hypercalcaemia, is often seen among middle-aged female patients, typically resulting from an underlying single-gland adenoma. Although patients may present with symptoms (nephrolithiasis, musculoskeletal discomfort, dehydration, or mood disturbance, to name a few), hypercalcaemia is rather frequently identified incidentally. In younger patients, a familial form of primary hyperparathyroidism must be considered, with a positive diagnosis mandating familial screening. Hyperparathyroidism-jaw tumour syndrome is one such autosomal dominant familial disorder, characterised by a mutation in the cell division cycle 73 (CDC73; also known as HRPT-2) tumour suppressor gene. This disorder is characterised by multiple pleiotropic phenomena, including recurrent primary hyperparathyroidism (and the effects of hypercalcaemia), neoplasms (such as uterine, renal, mandibular, and maxillary), and infertility. A patient not conforming to the classic candidacy for primary hyperparathyroidism requires consideration for a familial cause. Case Description. We present a rare diagnostic entity-hyperparathyroidism-jaw tumour (HPT-JT) syndrome-in a 36-year-old female with recurrent primary hyperparathyroidism, frequent nephrolithiasis, and infertility for 18 years prior to the diagnosis. We aim to promote awareness amongst medical professionals of this rare, but nonetheless essential differential diagnosis through a case report and review of the literature. Conclusion. Medical professionals must avoid diagnostic overshadowing and display a low threshold for genetic testing in younger patients with primary hyperparathyroidism. The importance of proper identification extends beyond the patient to their relatives and offspring.

Ossifying Fibroma in the Nasal Cavity of a 2-Year-Old Horse

Simple Summary

This article reports on the clinical features, diagnosis, and management of ossifying fibroma in the nasal cavity of a 2-year-old horse. Ossifying fibromas (OFs) are rare, benign, fibro-osseous neoplasms that occur more frequently in the rostral mandible of young horses (termed equine juvenile mandibular ossifying fibromas) but rarely in older horses. The occurrence of OF in young animals suggests developmental disorders or trauma as etiological factors. The local recurrence of OFs is common if they are not completely surgically excised, but metastatic spread is unusual. The presented case remained clinically asymptomatic until the mass obliterated the whole nasal cavity, causing severe breathing difficulties. The exact mass location was revealed using diagnostic images—namely, radiographs and computed tomography (CT) images. A concurrent problem of an underdeveloped and hypoplastic last premolar tooth of the maxilla was diagnosed. Because the mass was well-demarcated, the horse underwent standing surgery to remove the mass and the tooth. Histopathological diagnosis of ossifying fibroma was confirmed. The patient recovered uneventfully and remained free of disease at the 2-year postoperative follow-up.

Abstract

A 2-year-old mare of an unknown breed was referred to the clinic due to undetermined breathing difficulties. Physical examination revealed painless swelling rostral to the nasoincisive notch and a large, firm mass protruding from the left nostril. Radiographic examination of the head revealed a mass occupying the left nasal cavity and a displaced and hypoplastic last premolar of the left maxilla. The CT scan showed a well-demarcated heterogeneous mass measuring 22 × 9 × 5 cm (length × height × width) in the left nasal cavity attached to the roots of the displaced tooth and conchae. The surgery was performed on the standing horse. Firstly, due to the oblique position of the displaced tooth, the extraction was performed extra-orally through the trephination and repulsion of the maxillary bone. In the next step, a direct surgical approach was chosen for the caudal part of the mass via the osteotomy of the left nasal bone. The mass was bluntly separated from the conchae and removed through the nostril using Fergusson forceps. The histopathological characteristics of the mass led to the diagnosis of ossifying fibroma. The horse recovered completely in seven months, without recurrence after two years.

A rare presentation of cemento-ossifying fibroma in the maxilla: A case report

The basis of the problem: Cemento-ossifying fibroma is a benign fibro-osseous lesion of the jaw. It presents as a slow growing swelling which progressively enlarges if not surgically intervened. Cemento-ossifying fibroma revolves around the use of different terminologies and diagnostic criteria in proposing a strategic treatment plan. Method: The current article describes a rare occurrence of cement-ossifying fibroma affecting maxilla in a 44 year old female patient. Clinically, the lesion was painless and slow growing in nature. Computed tomography revealed a hypodense area in the right posterior maxilla measuring 19.07mm X 27.11mm. The lesion was surgically resected under general anesthesia and it was histopathologically confirmed to be cemento-ossifying fibroma. Results: Total enucleation/ resection of the osseous lesion must be timely ensured to prevent recurrence and also to achieve good prognosis which was done in the described case report. No recurrence was reported in the present case which had a follow up for 24 months. Conclusion: Although numerous controversies exist in the use of terminologies, a multi centric approach mandates to correlate clinically, radiographically and histologically to determine the treatment perspective.

Familial Hyperparathyroidism

Regulation of the serum calcium level in humans is achieved by the endocrine action of parathyroid glands working in concert with vitamin D and a set of critical target cells and tissues including osteoblasts, osteoclasts, the renal tubules, and the small intestine. The parathyroid glands, small highly vascularized endocrine organs located behind the thyroid gland, secrete parathyroid hormone (PTH) into the systemic circulation as is needed to keep the serum free calcium concentration within a tight physiologic range. Primary hyperparathyroidism (HPT), a disorder of mineral metabolism usually associated with abnormally elevated serum calcium, results from the uncontrolled release of PTH from one or several abnormal parathyroid glands. Although in the vast majority of cases HPT is a sporadic disease, it can also present as a manifestation of a familial syndrome. Many benign and malignant sporadic parathyroid neoplasms are caused by loss-of-function mutations in tumor suppressor genes that were initially identified by the study of genomic DNA from patients who developed HPT as a manifestation of an inherited syndrome. Somatic and inherited mutations in certain proto-oncogenes can also result in the development of parathyroid tumors. The clinical and genetic investigation of familial HPT in kindreds found to lack germline variants in the already known HPT-predisposition genes represents a promising future direction for the discovery of novel genes relevant to parathyroid tumor development.

Long-Term Clinical Course of Benign Fibro-Osseous Lesions in the Paranasal Sinuses

Objectives

Fibro-osseous lesions of the paranasal sinuses can present various clinical manifestations. This study aimed to report the long-term clinical course of benign fibro-osseous lesions (BFOLs) in the paranasal sinuses, including clinical and radiologic features.

Methods

Radiologically confirmed BFOLs between 1994 and 2016, with the exclusion of osteoma cases, were retrospectively reviewed. We compared demographic characteristics between the surgery and observation groups. The reasons for the imaging study, radiographic features, histopathology, and clinical course based on serial image scans were analyzed.

Results

In total, 183 subjects were selected from a thorough review of head and neck radiologic tests (n=606,068) at a tertiary referral hospital over 22 years. Patients’ mean age was 28.6±18.1 years, and 56.3% were males. A diagnostic imaging workup was performed in 55.7% of patients due to facial asymmetry, headache, skull mass, or other symptoms related to BFOLs. In other patients (37.7%), BFOLs were found incidentally on computed tomography or magnetic resonance imaging. The most common diagnosis was fibrous dysplasia, followed by ossifying fibroma, based on both radiologic exams and histopathologic results. In total, 42.6% of the patients underwent surgery because of subjective symptoms or esthetic concerns. The patients who underwent surgery were younger (P<0.001) and had a longer follow-up duration (P<0.001) than those who underwent observation. Patients who experienced lesion growth (11.5%) were younger (P<0.001) and had more lesion sites (P=0.018) than those who did not, regardless of surgical treatment. Five patients underwent optic nerve decompression, and one patient experienced malignant transformation.

Conclusion

BFOL in the paranasal sinuses is a rare disease, and most cases were observed without specific treatment. Surgical treatment should be considered in symptomatic patients with aggressive clinical features. Regular observation and management are needed, particularly in younger patients in their teens.

Incidence and Distribution of Jaw Pathologies among 0-15 Years Age Group at a Tertiary Rural Health-Care Center of Maharashtra: A Retrospective Study of 10 Years

Objective

This study was undertaken to investigate the prevalence of intraosseous jaw lesions among pediatrics (0-15 years of age) in a rural health-care center of Maharashtra and to determine the most common types of lesions and their distribution according to gender and anatomical site involved.

Study Design

Histopathological data were collected from a database of lesions classified as intraosseous jaw lesions dated between January 1, 2005, and December 31, 2015, from the archives of the Department of Oral and Maxillofacial Surgery, Rural Dental College, Maharashtra, India. All the cases of jaw cysts and tumors among children under 16 years of age group were segregated and scrutinized further under the headings of type of pathologies, anatomical locations where they are most commonly seen, and the age/gender most pertinent to these pathologies.

Results

The present study revealed that 114/3896 jaw lesions were pediatric jaw pathologies, of which odontogenic cysts were 67/114 and jaw tumors were 47/114. Among the cysts, 70% were developmental cysts and 30% were inflammatory cysts. The majority (71.6%) of the jaw cysts were found in the mixed dentition phase (7-15 years). Among the jaw tumors, 55% of them were categorized under odontogenic tumors and 45% were under fibro-osseous lesions. Similar to intraosseous jaw cysts, tumors of jaws were more prevalent under the age of mixed dentition, which was found to be 87%. Male predominance was seen and the overall male:female ratio was calculated as 1:0.52 and 1:0.5 for cysts and tumors, respectively. Mandibular posterior segment was found to be the most commonly encountered anatomical site in both the groups of cases.

Conclusion

A large number of cases were recorded, which led us to a path of interrogation through which the reason for increased incidence was extracted, and it was agreed that though the pathogenesis remains the same in every individual, routine health checkups and early diagnosis may reduce the incidence and aggressiveness of pathologies, respectively, which was lacking at the rural area.

Imaging of Mixed and Radiopaque Jaw Lesions

Radiopaque lesions and lesions of mixed density are less frequent than radiolucent lesions of the jawbones. They comprise a spectrum of odontogenic and non-odontogenic lesions. The latter group includes inherited and developmental disorders, osteomyelitis, and benign and malignant primary bone tumors and metastases. Most odontogenic radiopaque or mixed lesions are either related to the apex or more rarely to the crown of the tooth, although there are exceptions to this rule. Some lesions, such as a torus mandibularis and torus palatinus, have a characteristic location, whereas others show no relationship to the dentition. This article describes the most characteristic and prevalent radiopaque and mixed lesions of the jaws and their imaging characteristics. Paget's disease, fibrous dysplasia, and rare sclerotic bone diseases of the maxillofacial bones are discussed elsewhere in this issue. Careful correlation of clinical presentation, panoramic radiographs, cone beam computed tomography, and histopathology are the cornerstones for appropriate lesion characterization.

Ossifying fibroma in the maxilla and orbital floor: report of an uncommon case

Benign fibro-osseous lesions occur when normal bone is replaced by cellular fibrous connective tissue and mineralized structures. One rare type of these lesions is the ossifying fibroma (OF). The aim of this study is to report an unusual case of OF in a 57-year-old female. Physical examination showed facial asymmetry without any tenderness, fluctuation, ocular pain, or ophthalmoplegia. Imaging exams revealed a solid mass involving the left maxilla and orbital floor. Surgical resection was performed without any complications or sequelae, and the histopathological results confirmed OF. Although recurrence is rare in this condition, the patient remains under follow-up.

Three types of ossifying fibroma: A report of 4 cases with an analysis of CBCT features

Ossifying fibroma is a slow-growing benign neoplasm that occurs most often in the jaws, especially the mandible. The tumor is composed of bone that develops within fibrous connective tissue. Some ossifying fibromas consist of cementum-like calcifications, while others contain only bony material; however, a mixture of these calcification types is commonly seen in a single lesion. Of the craniofacial bones, the mandible is the most commonly involved site, with the lesion typically inferior to the premolars and molars. Ossifying fibroma of the jaw shows a female predominance. Some reports of ossifying fibroma have been published in the literature; however, this report continues the research on this topic by detailing 3 types of ossifying fibroma findings on panoramic radiographs and cone-beam computed tomographic images of 4 patients. The radiographs of the presented cases could help clinicians understand the variations in the radiographic appearance of this lesion.

A large maxillary cemento-ossifying fibroma superimposed with solitary bone cyst documented over 18 years: A case report

INTRODUCTION

Cemento-ossifying fibromas are rare, benign lesions of the head and neck regions. The origin of these lesions can be traced to the periodontal ligament, because its cells are able to form cement, lamellar bone, or fibrous tissue.

CASE PRESENTATION

A rare case report of a young Caucasian female with a COF is described including follow-ups. She remained untreated for several years despite early radiographic findings of the lesion without a definitive diagnosis. The patient ultimately underwent radical surgery and the whole lesion was removed. The subsequent histological examination confirmed the clinical diagnosis of a COF. Since then, the patient has been under regular clinical and radiological follow-ups.

DISCUSSION

This rare case report of a COF, documented over 18 years, shows the importance of consecutive therapy after radiologic and clinical findings, as such lesions continue growing and may subsequently lead to severe medical conditions. Therefore, complete surgical resection of COFs is advised to achieve good results in terms of health and recurrence.

CONCLUSION

Long-term follow-up of patients is required as recurrences can occur for up to 10 years following treatment. Well-planned radical and wide surgical resection of these lesions has proven not only to be effective in eliminating the aetiological factors, but can also achieve decent bone regeneration and aesthetic results with almost no deformation in the surgical site.

Focal cemento-osseous dysplasia

Focal cemento-osseous dysplasia (FCOD) is a benign fibro-osseous lesion of bone characterized by the replacement of normal bone by fibrous tissue and subsequently followed by its calcification with osseous and cementum-like material. It is mostly asymptomatic in nature and requires no treatment. When secondarily infected, it becomes symptomatic and intervention is required. Here, we report a case of symptomatic FCOD of mandible in a 52-year-old female patient. Histopathological evaluation of the biopsy specimen by ground sections and decalcified sections aided in the final diagnosis of the case.

Secondary aneurysmal bone cysts and associated primary lesions: imaging features of 49 cases

PURPOSE

To describe the imaging, anatomic, and clinical features of a series of secondary aneurysmal bone cysts (ABC) and to ascertain their most commonly associated primary bone lesions.

METHODS

Forty-nine cases of histopathologically proven secondary ABCs were retrospectively reviewed. Demographic data and clinical history were obtained. Radiographic, computed tomographic, magnetic resonance, and nuclear medicine imaging were analyzed. Lesion location, imaging characteristics, and associated primary lesions were documented. Linear regression analysis and Chi-squared testing was performed for statistical analysis.

RESULTS

Twenty-four males and 25 females were included, with an age range of 8-79 years (mean 29.7 + - 4.5 years). Eleven types of primary bone lesion were identified, with giant-cell tumor (n = 17, 35%), chondroblastoma (n = 11, 22%), fibrous dysplasia (n = 6, 12%), osteoblastoma (n = 4, 8%) and osteosarcoma (n = 4, 8%) being the most frequent. The lesions involved chiefly the long bone epiphyses (n = 25, 51%). Secondary ABC imaging findings and locations most closely approximated those of their primary counterparts, although fluid-fluid levels were seen at a higher frequency than previously reported in primary chondroblastoma (9/11, 82%), fibrous dysplasia (2/6, 33%), osteoblastoma (4/4, 100%), osteosarcoma (3/4, 75%), and chondromyxoid fibroma (1/2, 50%).

CONCLUSION

The most common primary lesions associated with secondary ABC were giant cell tumor and chondroblastoma, located in the long bone epiphyses. The majority of the secondary ABCs demonstrate predominant imaging characteristics typical of the primary bone lesions, but with a higher presence of fluid-fluid levels.

Gnathic Bones and Hyperparathyroidism: A Review on the Metabolic Bony Changes Affecting the Mandible and Maxilla in case of Hyperparathyroidism

Parathyroid glands secrete the parathyroid hormone that plays an essential role in bone remodeling. Excessive production of parathyroid hormone causes a common metabolic bone disorder known as hyperparathyroidism that is classified into primary, secondary, or tertiary. In hyperparathyroidism, the late bony complication is manifested as a giant cell osteolytic lesion called "brown tumor." Primary hyperparathyroidism is usually a sporadic disorder, but in minority of cases it occurs in inherited forms, and one of these forms is the hyperparathyroidism-jaw tumor syndrome, which is characterized by primary hyperparathyroidism and ossifying fibroma in the mandible and/or maxilla.

Comparison radical surgery versus conservative surgery to decrease post-operative recurrence in ossifying fibroma: systematic review

Background: Ossifying fibroma in craniofacial is a rare disease, benign, locally aggressive fibro-osseous tumor. In the recent 2017 WHO classifications, ossifying fibroma divided into 2 type, ossifying fibroma of odontogenic origin and juvenile ossifying fibroma. Choosing the right treatment that can reduce the recurrence rate are particularly challenging. In this systematic review we try to analyse related study to determine the best treatment for ossifying fibroma. Aim: The aim of this review to evaluate best treatment option and analysed level of recurrence in each type of treatment. Method: Collected Juvenile Ossifying Fibroma (JOF) and Ossifying Fibroma (OF) related Article from four different database (PubMed, Scopus, Cochrane Library, and Proquest). Study selection was done by using PRISMA strategy. Result: Eight retrospective case series studies were analyzed. Recurrence rate after surgery was 15.3%, most frequent recurrence occurs in conservative surgery. Recurrence rate after conservative surgery was 19.7%, compared with radical surgery which relatively lower in percentage, with recurrence rate after surgery was 10.6%. Conclusion: Juvenile Ossifying Fibroma, especially Trabecular Juvenile Ossifying Fibroma (TrJOF), show high recurrence percentage comparing other type. The first-choice management for treating OF was surgical approach. Types of surgery choose to depend on the aggressiveness and morbidity of the disease. Radical surgery was proven better to decrease level of recurrence compared with conservative surgery.

Ossifying fibroma in the mandibular angle mimicking metastatic clear cell renal cell carcinoma: A case report

RATIONALE

Ossifying fibroma is benign fibro-osseous neoplasm. The authors report a case of ossifying fibroma in the mandibular angle suspected as metastasis of clear cell renal cell carcinoma.

PATIENT CONCERNS

A 74-year-old man presented to the primary hospital complaining of frequent urination. A tumor in the left kidney was detected via an abdominal computed tomography scan. The patient then visited the Department of Urology at our hospital.

DIAGNOSES

According to whole-body imaging examinations, the patient was suspected of having renal cancer with mandibular metastasis. Also, a cystic lesion of the maxilla was revealed.

INTERVENTIONS

Left nephrectomy was performed by urologists, and the patient was diagnosed with clear cell renal cell carcinoma of the left kidney. Approximately 1 month later, resection with a safety margin of the mandibular lesion and removal of the maxillary lesion were performed by oral and maxillofacial surgeons.

OUTCOMES

The patient was diagnosed with ossifying fibroma of the mandible and an odontogenic keratocyst of the maxilla via a histopathological examination. Eighteen months have passed since the operation without clinical and imaging findings associated with recurrence.

LESSONS

Ossifying fibroma in the mandibular angle of elderly patients is extremely rare. Surgeons should consider the possibility of metastasis when osteolytic lesions of the jaw are found in patients with cancer.

Large ossifying fibroma of jaw bone: a rare case report

Ossifying fibroma (OF) is classified as, and behaves like, a benign bone neoplasm. It is often considered to be a type of fibro-osseous lesion (FOL). It can affect both mandible and the maxilla, particularly the mandible. This bone tumour consists of highly cellular, fibrous tissue that contains varied amounts of bone or cementum resembling calcified tissue. Present case is an unusual report of central ossifying fibroma involving the left side of mandible in an 18 year old female patient, who presented to the department with a painless hard swelling. The lesion was treated by surgical resection and reconstruction.

Cemento-ossifying fibroma of the mandible. A clinicopathological report

Cemento-ossifying fibromas are rare fibro-osseous benign neoplasms that affect the jaws. They are included in the group of mesodermal odontogenic tumors and commonly present as a progressively growing lesion that might attain enormous size with resultant deformity, if left untreated. A confusion prevails on the terminology, which can only be confirmed by histopathologic evaluation. A case of cemento-ossifying fibroma involving the right mandible is described in a 30 year-old female patient. The clinical, radiographic, histologic features are presented and the various differential diagnosis are discussed.

A Case Series of Fibro-Osseous Lesions of the Jaws

The aim of this case series was to reveal the difficulties in diagnosing fibro-osseous lesions with radiological and histopathological examinations and quantify the potential risk of infection to fibro-osseous legions. To analyze the concordance between radiological and histopathological diagnoses, this retrospective case series included patients who were clinically diagnosed with fibro-osseous lesions via radiological findings and excluded the patients who did not undergo histopathological examinations. This study also included the patients in whom histopathological results confirmed fibro-osseous legions when preoperative radiological diagnosis did not include fibro-osseous legions. Eleven patients (three men, eight women; median age 24.5 years, range 15-57 years) were enrolled. Although radiological diagnoses of fibrous dysplasia (FD) corresponded with histopathological diagnoses in seven patients, mismatches between radiological findings and histopathological results were found in three patients. In one patient, suspected diagnosis with radiological examinations was malignant lymphoma or FD. In two patients, the histopathological differentiation between FD and ossifying fibroma (OF) was difficult. One patient had lesion recurrence which was suspected to be OF with surgical findings and postoperative course after the initial surgery. In three patients, infections of FD were found. Preoperative diagnosis of OF with radiographic feature of unilocular radiolucency is difficult. In cases in which histopathological differentiation between FD and OF is difficult, operative findings should be used because OF is often found to be well-encapsulated and easily enucleated. Bone in FD showing mixed radiolucent-radiopaque may be vulnerable to infection.

Odontogenic tumors: where are we in 2017 ?

Odontogenic tumors are a heterogeneous group of lesions of diverse clinical behavior and histopathologic types, ranging from hamartomatous lesions to malignancy. Because odontogenic tumors arise from the tissues which make our teeth, they are unique to the jaws, and by extension almost unique to dentistry. Odontogenic tumors, as in normal odontogenesis, are capable of inductive interactions between odontogenic ectomesenchyme and epithelium, and the classification of odontogenic tumors is essentially based on this interaction. The last update of these tumors was published in early 2017. According to this classification, benign odontogenic tumors are classified as follows: Epithelial, mesenchymal (ectomesenchymal), or mixed depending on which component of the tooth germ gives rise to the neoplasm. Malignant odontogenic tumors are quite rare and named similarly according to whether the epithelial or mesenchymal or both components is malignant. The goal of this review is to discuss the updated changes to odontogenic tumors and to review the more common types with clinical and radiological illustrations.

[Relationship between different X-ray appearances and oral clinical manifestations of cemental dysplasia]

Cemental dysplasia is a non-neoplastic lesion and features different X-ray appearances that easily confuse dentists. This condition is often observed in conventional dental films or occasionally on panoramic radiographs. Cemental dysplasia is easily misdiagnosed as chronic periapical periodontitis, osteomyelitis, and tumor. In this paper, clinical mani-festations, imaging diagnosis, and the correlation between these variables are analyzed to achieve correct diagnosis.

Deletion of Menin in craniofacial osteogenic cells in mice elicits development of mandibular ossifying fibroma

Ossifying fibroma (OF) is a rare benign tumor of the craniofacial bones that can reach considerable and disfiguring dimensions if left untreated. Although the clinicopathological characteristics of OF are well established, the underlying etiology has remained largely unknown. Our work indicates that Men1-a tumor suppressor gene responsible of Multiple endocrine neoplasia type 1-is critical for OF formation and shows that mice with targeted disruption of Men1 in osteoblasts (Men1^Runx2Cre) develop multifocal OF in the mandible with a 100% penetrance. Using lineage-tracing analysis, we demonstrate that loss of Men1 arrests stromal osteoprogenitors in OF at the osterix-positive pre-osteoblastic differentiation stage. Analysis of Men1-lacking stromal spindle cells isolated from OF (OF-derived MSCs (OFMSCs)) revealed a downregulation of the cyclin-dependent kinase (CDK) inhibitor Cdkn1a, consistent with an increased proliferation rate. Intriguingly, the re-expression of Men1 in Men1-deficient OFMSCs restored Cdkn1a expression and abrogated cellular proliferation supporting the tumor-suppressive role of Men1 in OF. Although our work presents the first evidence of Men1 in OF development, it further provides the first genetic mouse model of OF that can be used to better understand the molecular pathogenesis of these benign tumors and to potentially develop novel treatment strategies.

Peripheral osteoma, compound odontoma, focal cemento-osseous dysplasia, and cemento-ossifying fibroma in the same hemimandible: CBCT findings of an unusual case

Peripheral osteoma is the most common subtype of osteoma that arises most frequently in the craniofacial bones. It may occur at any age with a male-to-female ratio of 2:1. Peripheral osteoma may affect the mandible, particularly the ramus and the condyle. Compound odontoma is a subtype of odontoma that occurs in young subjects without gender predilection. It affects the maxilla more frequently than the mandible. Focal cemento-osseous dysplasia and cemento-ossifying fibroma are 2 benign fibro-osseous lesions with a female predominance that occur most commonly in the posterior region of the mandible. We report the first case involving the simultaneous occurrence of these 4 benign lesions in the same hemimandible diagnosed by CBCT.

Ossifying fibroma: an uncommon differential diagnosis for T2-hypointense sinonasal masses

Ossifying fibroma is a benign fibro-osseous lesion that occurs most commonly in the mandible of female patients. In rare cases, it affects the nasal cavity. The magnetic resonance imaging features may vary depending on the amount of fibrous and bony tissue in its composition. In these tumors, T2-hypointensity is a feature described in the peripheral ossified areas of the lesion, but it may present diffusely, especially when the degree of ossification is extensive. In this scenario, this particular characteristic on T2-weighted imaging is superimposable to the commonly described appearance of other lesions, such as non-Hodgkin's lymphoma, melanoma, and other sinonasal neoplasms with high cellularity and high nucleocytoplasmic ratio. In the present study, we report a case of ossifying fibroma of the nasal cavity that presented as a diffusely and homogeneously T2-hypointense mass, a finding that may cause difficulty in the differential diagnosis with other expansive sinonasal lesions.