Tumours and pseudotumorous lesions of the temporomandibular joint: a diagnostic challenge.

Tumours and pseudotumorous lesions originating from the synovial membrane of the temporomandibular joint are rare. We report a series of six cases of such disorders. There were two cases of synovial chondromatosis, two of calcium pyrophosphate dihydrate crystal deposition disease, one nodular synovitis and one synovial sarcoma. Three patients were female and three were male. Their ages ranged from 36 to 70 years. All had atypical clinical and radiographical presentation. The prevalence, clinical and radiographical findings and pathological features of each disease entity are discussed and a review of the literature is made concerning all tumours and pseudotumours arising from the temporomandibular joint.

Mixed desmoplastic primitive neuroepithelial tumor of infancy: a light microscopic, immunocytochemical, ultrastructural and genetic study.

We describe a case of a desmoplastic brain tumor which was initially resected from the right fronto-temporal region in a 2 year-old boy. This nodular, calcified tumor was vascularized by the internal carotid artery and the middle meningeal artery branches. Grossly, it contained several mucoid cysts. Light microscopy showed cords or nests of small cuboidal cells surrounded by a loose connective tissue and desmoplastic areas containing fibers and spindle cells. The cuboidal cells expressed epithelial, neuronal and neuroendocrine markers. Some foci of spindle cells showed glial differentiation. The tumor recurred 16 months later and displayed some characteristics of the small cell neuroepithelial component, mitoses being conspicuous. Electron microscopy revealed undifferentiated clear cells, some containing neurosecretory granules. Karyotyping demonstrated the following formula: < 15 > 46, t(8;11) (q13; q11). The chromosome 11 breakpoint was different from that described in Ewing's sarcoma. This isolated translocation has not been previously reported to our knowledge. These unusual features lead us to report this case and to discuss its pathogenesis.