Odontogenic Myxoma: Systematic review and bias analysis

Infantile Sinonasal Myxoma Is Clinically and Genetically Distinct From Other Myxomas of the Craniofacial Bones and From Desmoid Fibromatosis

Sinonasal myxomas are rare benign tumors of the maxillary bone and sinus. There is published evidence that sinonasal myxomas occurring in children up to 3 years of age ("infantile sinonasal myxomas") are clinically distinctive and harbor Wnt signaling pathway alterations. Here, we characterized 16 infantile sinonasal myxomas and compared them to 19 maxillary myxomas and 11 mandibular myxomas in older patients. Clinical follow-up was available for 21 patients (46%) overall (median: 2.6 y; range: 4 mo to 21 y), including 10 of 16 infantile sinonasal myxomas (62%). None of the 8 resected infantile sinonasal myxomas recurred, despite positive margins in 6 of them. One incompletely resected infantile sinonasal myxoma underwent partial regression without additional treatment. In contrast, 4 of the 11 other myxomas with follow-up recurred (36%), including one that recurred twice. Imaging studies demonstrated all infantile sinonasal myxomas to be expansile lesions arising from the anterior maxillary bone adjacent to the nasal aperture, with peripheral reactive bone formation. Histologically, infantile sinonasal myxomas showed short, intersecting fascicles of bland fibroblastic cells with prominent stromal vessels. Examples with collagenous stroma showed some morphologic overlap with desmoid fibromatosis, although none showed infiltrative growth into adjacent soft tissue. Immunohistochemistry demonstrated nuclear β-catenin expression in 14 of 15 infantile sinonasal myxomas (93%), in contrast to 4 of 26 other myxomas of craniofacial bones (15%). Smooth muscle actin was expressed in only 1 of 11 infantile sinonasal myxomas (9%). Next-generation sequencing was successfully performed on 10 infantile sinonasal myxomas and 7 other myxomas. Infantile sinonasal myxomas harbored CTNNB1 point mutations in 4 cases (D32Y, G34E, G34R, and I35S), and none harbored alterations to the phosphorylation sites T41 and S45 that are altered in 99% of CTNNB1 -mutant desmoid fibromatoses. Three tumors showed alterations consistent with biallelic APC inactivation. Three infantile sinonasal myxomas that showed strong nuclear β-catenin expression were negative for CTNNB1 and APC alterations. Sequencing was negative for CTNNB1 or APC alterations in all 7 myxomas of craniofacial bones in older patients. Four of these myxomas in older patients (57%) showed copy number alterations, and all lacked known driving alterations. These findings support the notion that infantile sinonasal myxomas are clinically and genetically distinctive, and we propose the use of the diagnostic term "infantile sinonasal myxoma" to distinguish this tumor type from other myxomas of the craniofacial bones. Infantile sinonasal myxoma should be distinguished from desmoid fibromatosis because of its unique clinical presentation, more indolent clinical behavior, different morphology, different immunohistochemical profile, and different genetics. Given its indolent behavior even when marginally excised, infantile sinonasal myxoma can be managed with conservative surgery.

Surgical management of odontogenic myxomas: A case series

INTRODUCTION

Odontogenic myxoma is a relatively rare bone tumor involving exclusively the jaws. Despite its benign nature, odontogenic myxoma can exhibit aggressive, locally invasiveness and has a high potential of recurrence. Surgical treatment can be conservative of radical. The choice of surgical procedure is controversial, and there are no established guidelines.

CASE SERIES PRESENTATION

We present a case series of three cases of odontogenic myxomas. This case series illustrates the variability of the radioclinical presentation of odontogenic myxoma and the resulting surgical management, ranging from simple enucleation to mandibular interruptive resection surgery with free flap reconstruction.

DISCUSSION AND CONCLUSION

Through this case series, we highlighted and described decision criteria contributing to treatment choice and summarized this in an algorithm. Radiological tumor characteristics and also patient specific factors such as age need to be considered to make a personalized decision to each patient.

Prominent osteolysis in the maxilla: case report of an odontogenic fibroma mimicking a cyst

BACKGROUND

Odontogenic fibroma (OF) is a rare benign odontogenic tumor of ectomesenchymal origin, mostly affecting the tooth-bearing portions of the jaws in middle-aged patients. Whilst small lesions tend to be clinically asymptomatic, varying unspecific clinical symptoms occur with an increase in size and may mimic odontogenic or other maxillofacial bone tumors, cysts, or fibro-osseous lesions of the jaws.

CASE PRESENTATION

A 31-year-old female patient presented with a hard, non-fluctuating protrusion in the vestibule of the upper right maxilla. It was visualized on cone beam computed tomography (CBCT) as space-occupying osteolysis with the displacement of the floor and facial wall of the maxillary sinus, mimicking a cyst-like lesion. The tissue was surgically removed and identified as an OF in the histopathological examination. One year after the surgery, restitution of regular sinus anatomy and physiological intraoral findings were observed.

CONCLUSIONS

This case report emphasizes that rare entities, like the maxillary OF presented, often demonstrate nonspecific clinical and radiological findings. Nevertheless, clinicians need to consider rare entities as possible differential diagnoses and plan the treatment accordingly. Histopathological examination is essential to conclude the diagnosis. OF rarely recur after proper enucleation.

Myxoma of the upper lip: a case report and brief review of the literature

Myxomas are rare neoplasms of mesenchymal origin, which consist of many undifferentiated stellate and spindle-shaped cells in abundant loose myxoid stroma with collagen fibers. A 74-year-old patient presented in our oral and maxillofacial department with a slow growing mass within the upper lip. The mass was surgically excised in the toto, followed by a histological and immunohistochemical examination. The findings revealed that it was a myxoma. These tumors are very rare and should be included in the differential diagnosis of damage of the upper lip. As long as the myxoma is properly removed, there is no risk of recurrence.

[Use of current imaging tools for the study of odontogenic myxoma. A review of the literature]

Odontogenic myxoma (OM) is currently classified as a benign tumor of ectomesenchymal origin, observed between the second and fourth decade of age, with a predilection in women and predominance in the mandibular region, composed of rounded and angular cells embedded in an abundant myxoid stroma, of aggressive biological behavior, having the characteristic of being locally infiltrative. Tumor cells spread in the intratrabecular space beyond the bone limit, making it difficult to determine the edge of the tumor, even without cortical continuity, presenting intermittent direct contact with soft tissue; the appearance can be unilocular (small lesions), or commonly the typical image is that of a destructive lesion with poorly defined borders with a multilocular growth pattern, for which the use of advanced medical images such as Cone Beam Computed Tomography (CTHC), Computed Tomography (CT), Magnetic Resonance Imaging (MRI), are useful to establish an adequate diagnosis with the ability to point out the characteristics of OM with precision and three-dimensional perspective. This review presents a systematic analysis of the types of imaging tools currently used for the study of OM.

Odontogenic myxoma with pain and uncommon histological feature in the mandible: A case report and review the literature

Odontogenic myxoma (OM) is a rare benign painless, slow-growing lesion with local aggressive behavior. Pain and sensory disturbance and fibro-osseous appearance in histopathology have been rarely reported in OM. The authors reported a 52-year-old male case presented with a large gingival mass around a mobile mandibular right first molar extended to the distal aspect of the third molar. Microscopic examination of the incisional and excisional biopsy revealed an OM with numerous newly formed bone or cementum-like material present throughout the specimen like those seen in fibro-osseous lesions. For avoiding to recurrence, a segmental mandibulectomy was performed and a metal plate was inserted to the right mandible defect under general anesthesia. Rehabilitation was completed with the placement of implants. We review and discuss about this variety.

Odontogenic myxoma of the anterior mandible: Case report of a rare entity and review of the literature

This report intends to compare classic presentations of odontogenic myxoma in contrast to our case. We also suggest a comprehensive evaluation of lesions and strongly advocate against premature treatments before reaching a definitive diagnosis.

Central Odontogenic Myxoma: A Radiographic Analysis

Objective

This study aimed to determine the radiographic characteristics of odontogenic myxomas (OMs) and their associations.

Materials and Methods

The study enrolled radiographs of patients taken between 2005 and 2019 with a confirmed histopathological diagnosis of central OM. OM radiographic features were evaluated, including location, border, locularity, involved area, the number of included teeth, root resorption, tooth displacement, bone expansion, bone perforation, and periosteal reaction. Fisher's exact test was used for statistical analysis.

Results

Significant associations were found between the OM border and the affected jaw (p=0.036), locularity (p=0.036), involved areas (p=0.009), and bone perforation (p=0.036). OMs with an ill-defined border were associated with maxillary lesions, multilocularity, dentate areas, and cortical bone perforation. The number of included teeth (2 or fewer or 3 or more) was significantly associated with locularity (p=0.010), involved area (p=0.045), and bone expansion (p=0.010). Larger OMs including 3 or more teeth, were associated with a multilocular appearance, dentate areas, and bone expansion.

Conclusion

The border of OM and the number of included teeth are related to other radiographic appearances. Understanding these relationships could help in treatment decisions and help better understand the nature of OM.