Academic literature on the topic 'Jawbone tumors'

Malignant peripheral nerve sheath tumours (MPNSTs) are rare, aggressive softtissue sarcomas associated with poor prognosis, that most commonly affect patients aged20 to 50 years, but have also been reported in children. The tumour is usually found in lowerextremities and only 10% to 20% of all lesions occur in head and neck region thus making ita rare entity. Central involvement, particularly in the jawbones is quite unusual. There is littlereported in literature on these tumors in Africa. Here we report a rare case of intraosseousMPNSTS occurring in the mandible in a 12-years old girl. The biological behavior and diagnosticchallenges of this rare malignancy are discussed.

ABSTRACT Cementifying fibromas are rare fibro-osseous lesions that affect the jawbone and that are included by Gorlin in the group of mesodermal odontogenic tumours. Four separate categories have been identified: Periapical cemental dysplasia, benign cementoblastoma, cementifying fibroma and a rare gigantiform variety. The current case is reported because of rarity of such lesions and the paucity of information concerning them in the dental literature. We believe that this case illustrates many of the clinical, radiographic and histologic features associated with cemento-ossifying tumours.

Gingival squamous cell carcinoma (SCC) frequently invades the maxillary or mandibular bone, and bone destruction is known as a key prognostic factor in gingival SCCs. Recently, Neurokinin 3 receptor (NK-3R), the receptor ligand for NK-3, which is a member of the tachykinin family expressed in the central nervous system, was identified through pathway analysis as a molecule expressed in osteoclasts induced by the hedgehog signal. Although the expression of NK-3R has been detected in osteoclast and SCC cells at the bone invasion front, the relationship between NK-3R expression and the prognosis of gingival SCC patients remains unclear. In the present study, we retrospectively reviewed 27 patients with gingival SCC who had undergone surgery with curative intent. Significantly higher NK-3R expression in tumor cells was found in a case of jawbone invasion than in a case of exophytic poor jawbone invasion. On the other hand, no significant association was observed between NK-3R tumor-positive cases and tumor size, TNM stage, or tumor differentiation. The survival rate tended to be lower in NK-3R tumor-positive cases, but not significantly. However, the disease-specific survival rate was significantly lower in patients with a large number of NK-3R-positive osteoclasts than in those with a small number of them at the tumor bone invasion front. Our results suggest that NK-3R signaling in the gingival SCC bone microenvironment plays an important role in tumor bone destruction and should be considered a potential therapeutic target in advanced gingival SCC with bone destruction.

Afin de mieux comprendre les bases physiopathologiques des tumeurs osseuses des mâchoires, nous avons étudié deux modèles de tumeurs associées à des mutations génétiques connues : la tumeur kératokystique odontogène (TKO), liée à la mutation de PTCH1, et le chérubinisme, lié à la mutation de SH3BP2. Au regard des travaux d’oncogénétique, nous formulons l’hypothèse que le développement des tumeurs ostéolytiques bénignes des mâchoires de l’enfant et leur agressivité repose sur un mécanisme génétique. Nous avons montré que la présence d’une mutation de PTCH1 (germinale avec syndrome de Gorlin) dans les TKO était un facteur de mauvais pronostic, stimulant un centre tumoral secondaire, responsable de lésions à distance, mais que cette agressivité pouvait aussi être liée à des mécanismes inflammatoires. Dans le chérubinisme, nous avons montré que la mutation était responsable du phénotype, mais que le type de mutation n’influençait pas le pronostic ni l’agressivité. L’agressivité tumorale est liée au phénotype des cellules géantes multinucléées (cellules myéloïdes à différenciation macrophagique ou ostéoclastique). Nous avons montré, que le modèle murin ne pouvait pas s’appliquer à la pathologie humaine, avec notamment un rôle très secondaire du TNF-α. Enfin nous avons démontré le rôle important de NFATc1 dans la physiopathologie du chérubinisme qui nous a permis de proposer, le tacrolimus, comme le premier agent thérapeutique efficace. Nos résultats suggèrent que les mutations induisent la pathologie et que les changements du microenvironnement (liés à la flore buccale ou à l’éruption dentaire) entretiennent la pathologie<br>To determine pathophysiological bases of jawbone tumors, we studied two genetic models of jawbone tumors: keratocystic odontogenic tumors (KOT) associated to PTCH1 mutation and cherubism associated to SH3BP2 mutation. From oncogenetic theory, we postulate that genetic background controls the development of benign children jawbone tumors. From our work, we demonstrated that PTCH1 mutation (germline mutation in Gorlin syndrome) was an unfavorable prognosis factor for KOT, leading to distant and independent daughter tumors. Moreover, we showed, that chorionic inflammation was associated with a high recurrence rate. In cherubism, SH3BP2 mutation produced cherubism phenotype, but the type of mutation did not affect the aggressiveness of the disease. Cherubism aggressiveness was determined by the phenotype of giant multinucleated cells (whether osteoclasts or macrophages). Furthermore, we showed that murine model could not be transposed to human pathology; indeed it appeared that TNF- α did not play a critical role in human cherubism. On the other side, we showed that NFATc1 played a crucial role in cherubism pathophysiology; this observation allowed us to propose, the tacrolimus, as an effective treatment for this disease. Our results suggest that genetic background induced tumor development, and that microenvironment changes (due to flora of the oral cavity and to teeth eruptions) are responsible to the maintenance and the progression of the disease