A successfully treated inflammatory myofibroblastic tumor of the mandible with long-term follow-up and review of the literature

Inflammatory myofibroblastic tumor (IMT) of the oral cavity is an extremely rare clinical and pathological disease entity. It was originally described in the lung but has recently been reported in various anatomic sites. We report such a case of inflammatory myofibroblastic tumor of the mandible in a 14-year-old girl. The patient presented with an aggressive ulcerative soft tissue mass of 3 months duration in the mandibular molar gingiva. Histologically, the lesion was composed of fibroblastic or myofibroblastic spindle cell proliferations with infiltrative margins in an inflammatory background. Immunohistochemically, the fibroblastic or myofibroblastic spindle cells were positive for vimentin, α-smooth muscle actin, and Ki-67 (MIB-1) but negative for desmin, pan-cytokeratin, S-100 protein, CD34, CD68, CD99, bcl-2, β-catenin, estrogen receptor, progesterone receptor, ALK-1, and p53. These spindle cells were focally and weakly Ki-67- (MIB-1-) positive. The MIB-1 labeling index was 5%. The results of in situ hybridization for Epstein-Barr virus-encoded-RNA were negative. The ratio of IgG4+/IgG+ plasma cells was about 10%. A pathological diagnosis of inflammatory myofibroblastic tumor was made. The postoperative course was uneventful, and the patient has had no recurrence in the 10-year follow-up period. Although no evidence of oral inflammatory myofibroblastic tumor recurrence or malignant transformation has been reported, it has been observed that in inflammatory myofibroblastic tumors of other regions, a prolonged follow-up is necessary after surgical resection. No other case of an IMT patient under 20 years of age has appeared in either the English or the Japanese literature.     

A physicomathematical approach to the structure of the mandible

Summary Classical methods of anatomical study and experimentation have reached an endpoint with respect to the advancement of our knowledge of certain aspects of bone, i.e. its mechanical properties, investigation of the constraints acting on bone and the organization of bone allowing resistance to such mechanical stress. Indeed, current knowledge is rather limited regarding bone as a material. Furthermore, bone from the cadaver cannot be considered a reliable source of study material since its physicochemical composition and mechanical properties are highly different from those of living bone. The types of experimentation used to date, although allowing to study the phenomena occuring on the surface of the bone, do not allow to evaluate those that occur within the bone without modification of its mechanical features. Finally, the number and complexity of the parameters to be taken into account in this respect largely supersede the possibilities of classical study techniques.Accordingly, new types of methodology are required to evaluate the many parameters involved, to perform the corresponding computations and resolve the great number of unknown variables. Such methodology must allow experimentation to be performed without modifying the object of study and to determine the phenomena occuring within the bone itself, i.e. the mandible.A method of computer assisted simulation of a physicomathematical model was used to analyse the structural properties of the mandible. This method was based on that used for the computation and elaboration of large metal structures (offshore drilling platforms), structures submitted to special stress (resistance to force 7 earthquake of the new extension to the radioactive waste disposal factory at the Hague) or aeronautical structures composed of composite material.

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Approche physico-mathématique structurale de la mandibule

Résumé L'étude des propriétés mécaniques de l'os, celle des contraintes qu'il subit, la manière dont il est organisé pour résister à ces contraintes s'avèrent déboucher sur une impasse si l'on se contente des méthodes classiques d'études et d'expérimentations.En effet, nous n'avons actuellement qu'une connaissance très limitée de l'os en qualité de matériau. Le matériau d'expérimentation, l'os de cadavre ne peut être considéré comme fiable, sa constitution physico-chimique et ses propriétés étant par trop différentes de celles de l'os vivant. Le type même des expérimentations utilisées, s'il permet bien d'étudier ce qui se passe à la surface de l'os ne permet pas de prendre en compte ce qui se passe à l'intérieur de celui-ci sans en modifier les caractéristiques mécaniques. Enfin, le nombre et la complexité des paramètres à prendre en compte dépassent largment les possibilités des techniques classiques. C'est pourquoi, il est nécessaire de faire appel à des méthodologies nouvelles capables de prendre en compte un nombre très élevé de paramètres, de les calculer et de résoudre un nombre très important d'inconnues. Ces méthodologies doivent permettre l'expérimentation sans modifier l'objet de l'expérience et de calculer ce qui se passe à l'intérieur même de la mandibule.Cette méthode de simulation sur modèle physico-mathématique par informatique utilisée pour le calcul et l'élaboration des grandes structures métalliques (plate-forme off shore), celui de structures placées dans des conditions de contraintes particulières (prise en compte des tremblements de terre de magnitude 7 pour l'extension de l'usine de La Hague) ou bien celui des structures aéronautiques à matériaux composites a été ici appliquée à l'étude structurale de la mandibule.

     

Malignant lymphoma of the mandible. A new case

Primary extranodal malignant lymphoma is relatively rare. Clinical and radiological features may lead to the misdiagnosis of chronic osteomyelitis. We report a case of primary non-Hodgkin's lymphoma that involved the mandibular region in a 53-year-old man. Differential diagnosis with other mandibular diseases is difficult because there is a non specific clinico-radiological features and the difficulty of histologic interpretation. This pathology is important to recognize because of specific treatment. Global prognosis is relatively favorable if the lesion is localized.     

MRI of the mandible

Eighteen patients with abnormalities of the mandible and two normal volunteers were studied with MRI. Correlation was made with MR, CT, plain X-rays, clinical examination, and surgical findings when possible. In primary tumors of the mandible, MR was able to differentiate between solid and cystic lesions. In the cases of secondary invasion of the mandible by malignant tumors, MR was able to demonstrate replacement of the normal high signal bone marrow by low signal tumor. In some cases, the extent of marrow involvement shown on MR and confirmed at surgery was significantly underestimated by clinical examination, plain films, and CT. From this limited experience, it appears that MR may play an important role in imaging pathology of the mandible.     

Osteoradionecrosis of the mandible

Osteoradionecrosis is a major complication of surgery or trauma in previously irradiated bone in the absence of tumor persistence. Radiation-induced vascular insufficiency rather than infection causes bone death. It occurs most commonly in the mandible after head and neck irradiation. Risk factors include the total radiation dose, modality of treatment, fraction size and dose rate, oral hygiene, timing of tooth extractions as well as the continued use of tobacco and alcohol. This condition is often painful, debilitating, and may result in significant bone loss. The recommended treatment guidelines are irrigation, antibiotics, hyperbaric oxygen therapy, and surgical techniques, including hemimandibulectomy and graft placements.     

Massive osteolysis of the mandible

This report deals with a massive osteolysis, which is a rare disease characterized by the progressive dissolution of contiguous osseous structure, occurring in the mandible of a 46-year-old Japanese female. Histopathologic examination of the amputation material revealed that the mandibular body, ramus, condylar and coronoid processes were completely replaced by fibrous tissue, but inferior alveolar nerve and artery in the lesion were intact. A few small islands of osteoid tissue or immature fibrous bone were seen in the lesion. In the transitional area between the lesion and normal bone, active absorption of bone trabeculae was in progress and intertrabecular spaces were occupied by densely packed fibroblastic cells, however, angiomatous proliferation of vessels was not observed. A few bone trabeculae were surrounded by osteoclasts, but osteoclasts might not play a primary etiological role in massive osteolysis.     

Metastatic transitional-cell carcinoma to the mandible: A case report

Transitional-cell carcinoma to the mandible is an uncommon occurrence. Only three cases have been reported in the literature. This is a case report of such a metastasis, the first diagnosed by fine-needle aspiration. Emphasis is placed on the cytologic features of the tumor cells.     

Establishment and characterization of new cell lines derived from melanotic neuroectodermal tumor of infancy arising in the mandible

Three cell systems (MINT1/2/3) derived from a melanotic neuroectodermal tumor of infancy (MNTI) arising in the mandible of a 1-month-old newborn boy have been established, and their cytological natures have been characterized. The cells had immunopositivities for pan-keratin, vimentin, neuron-specific enolase, S-100 protein and melanoma-associated antigen (HMB-45). These immunohistochemical phenotypes were basically the same as those observed in tissue sections, in which, synaptophysin, myelin basic protein, c-myc gene products, carcinoembryonic antigen, and epithelial membrane antigen were also immunolocalized in tumor cells. Karyotyping analyzes revealed that the chromosome numbers of the three cell systems ranged from 60 to 67 with 3n ploidies, and that there were many structural aberrations, such as del(11)(q13), del(22)(q13), add(2)(p11), add(7)(q22), extra copies for chromosomes 1, 2, 3, 5, 7, 9, 10, 11, 12, 16, 20, and 22, der(9)t(9;13)(p13;q12)add(9)(q34), and der(13;21)(q10;q10), which were shared by the three cell systems, while der(19)t(11;19)(q13;p13) was found in MINT1 and MINT3. When stimulated by endothelin-3 and vitamin D(3), the cells had spinous cell shapes with immunopositivities for HMB-45, neurofilament protein and glial fibrillary acidic protein, which indicated more neural differentiation. The established cell systems will be useful for further investigation on the molecular and genetic basis of MNTI to understand its pathogenesis, which is largely unknown.     

A study of the position of the mandibular foramen in the adult human mandible

Eighty dry, adult human mandibles of East Indian ethnic origin and bilateral eruption of third molar teeth were examined to measure the location of the mandibular foramen. The position of the foramen was found to be variable. However, the foramen was predominantly located at the anteroposterior midpoint of the ramus halfway between the mandibular notch and the lower surface of the mandible and two thirds of the way down a line joining the coronoid process to the angle of the mandible. In the majority of the mandibles studied the foramen was located below the occlusal surfaces of the molar teeth. It is concluded that the marked variability in the position of the mandibular foramen may be responsible for an occasional failure to block the inferior alveolar nerve.     

Salivary gland tumors of the mandible

Primary central salivary gland carcinomas of the mandible are uncommon neoplasms. Consequently, their proper diagnosis is often in doubt. We retrospectively studied the cases of 16 patients treated at The University of Texas M. D. Anderson Cancer Center and the Institut Gustave Roussy from 1950 to 1990. Patients ranged in age from 24 to 76 years (mean, 51 years). Nine patients were women and seven were men. Each case involved either the angle or the posterior body of the mandible. Swelling, pain, and trismus were the most frequent complaints. For all patients, radiography revealed a cystic defect resembling an osteolytic odontogenic lesion or metastasis. Five histologic types of carcinoma were diagnosed: seven cases of mucoepidermoid carcinoma (five low-grade and two high-grade), four cases of adenoid cystic carcinoma, two cases of adenocarcinoma, two cases of acinic-cell carcinoma, and one case of epithelial-myoepithelial carcinoma. All patients were treated with wide surgical excision. Eight patients received postoperative irradiation. Five patients with low-grade mucoepidermoid carcinoma, two with acinic-cell carcinoma, and one with epithelial-myoepithelial carcinoma were free of disease 2 to 15 years after initial treatment (mean, 6.2 years). Two patients with adenoid cystic carcinoma are living with lung metastasis. The remaining six patients died of their carcinomas within 4 years after initial treatment. Because of their unique morphology and clinical behavior, these tumors should be distinguished from other intraosseous neoplasms of the mandible, including those with clear-cell patterns.     

Aneurysmal bone cyst of the mandible

The clinical features, radiological findings, microscopic examination and treatment of a case of aneurysmal bone cyst have been discussed. The histopathological examination is the only way to confirm the diagnosis of this interesting bone lesion which rarely affects the jaws.     

Logarithmic growth of the hominoid mandible

The growth of the basal unit of the mandible was studied by plotting the position, relative to the median plane, of the oval, mandibular and mental foramina in immature and adult skulls of Man, chimpanzee and gorilla. In Man, the basal unit was found to grow out along a constant logarithmic spiral. In the apes, the basal unit grew along a progressively unfolding logarithmic spiral, the amount of unfolding being greater in the gorilla than in the chimpanzee. It is argued that the mode of growth seen in the apes evolved, as these forms became more prognathous, because it requires less compensatory rotation of the mandible, while the mode seen in Man is probably closer to that which occurred in the common ancestral form.