Neurofibroma in the articular disc of the temporomandibular joint: a case report

Craniofacial bone alterations in patients with neurofibromatosis type 1

Osseous manifestations of neurofibromatosis 1 (NF-1) occur in a minority of the affected subjects but may be because of significant clinical impairment. Typically, they involve the long bones, commonly the tibia and the fibula, the vertebrae, and the sphenoid wing. The pathogenesis of NF-1 focal osseous lesions and its possible relationships with other osseous NF-1 anomalies leading to short stature are still unknown, though it is likely that they depend on a common mechanism acting in a specific subgroup of NF-1 patients. Indeed, NF-1 gene product, neurofibromin, is expressed in all the cells that participate to bone growth: osteoblasts, osteoclasts, chondrocytes, fibroblasts, and vascular endothelial cells. Absent or low content of neurofibromin may be responsible for the osseous manifestations associated to NF-1. Among the focal NF-1 osseous anomalies, the agenesis of the sphenoid wing is of a particular interest to the neurosurgeon because of its progressive course that can be counteracted only by a surgical intervention. The sphenoid wing agenesis is regarded as a dysplasia, which is a primary bone pathology. However, its clinical progression is related to a variety of causes, commonly the development of an intraorbital plexiform neurofibroma or the extracranial protrusion of temporal lobe parenchyma and its coverings. Thus, the cranial bone defect resulting by the primary bone dysplasia is progressively accentuated by the orbit remodeling caused by the necessity of accommodating the mass effect exerted by the growing tumor or the progression of the herniated intracranial content. The aim of this paper is to review the neurosurgical and craniofacial surgical modalities to prevent the further progression of the disease by "reconstructing" the normal relationship of the orbit and the skull.

A combination of skeletal deformations of the dorsal mandible and temporomandibular region detected in orthopantomograms of patients with neurofibromatosis type 1 indicates an associated ipsilateral plexiform neurofibroma

PURPOSE

Neurofibromatosis type 1 (NF1) is a tumour suppressor syndrome and also a bone disease. In the craniofacial region, local skeletal deformities have been recorded in patients with NF1. Obvious syndrome-related alterations of the jaws are particularly conspicuous in the mandible. Here we aimed to analyse the mandibular alterations of NF1-affected individuals from orthopantomograms (OPGs).

MATERIALS AND METHODS

This study analyses 358 OPGs of 358 patients (mean age, 34.63 years; range, 12.57-69.13 years). The OPGs of 179 patients of Caucasian origin with NF1 were investigated (mean age, 34.84 years; range, 12.83-68.89 years; 44.13% male, 55.86% female). The radiographic findings were compared to those obtained from OPGs of sex- and age-matched controls.

RESULTS

Characteristic deformations of the bone regions of interest occur in NF1 patients, especially in patients with plexiform neurofibroma of trigeminal nerve. These findings are always one-sided. The co-occurrence of several skeletal deformations can be expected with very high probability in this patient group.

CONCLUSION

The radiological sign of the unilateral deformed mandible should be included in the diagnostic criteria for NF1. In addition to the diagnostic value in this syndrome, these findings are important for avoiding surgical complications in planned interventions in this region.

Neurofibromatosis Type 1 in the Mandible

Neurofibromatosis type 1 (NF1) was first described in 1882 as a hamartomatous disorder of neural crest derivation. We present the imaging of a 65-year-old woman with NF1. Computed tomography revealed that there were three major findings presented: skeletal deformity, an area of fat (probably related to mesodermal dysplasia), and benign neoplasm within the masticator space. Moreover, masticatory muscles were hypoplastic.

Sacroiliac Joint Involvement in von Recklinghausen Neurofibromatosis

Neurofibromatosis (NF) type I is a genetic disorder caused by a mutation of the NF type I gene. This disease is associated with a variety of skeletal manifestations. In this article, we report a 33-year-old female patient with a known history of von Recklinghausen's disease and inflammatory right buttock pain. Diagnostic imaging pointed out unilateral sacroiliitis possibly of a septic origin. Sacroiliac biopsy showed histological patterns consistent with NF. This case report summarizes an exceptional localization of NF mimicking the imaging of infectious sacroiliitis.

Imaging findings of neurogenic tumours in the head and neck region

OBJECTIVE

The aim of this study was to describe the CT, MRI and ultrasonography findings of five cases of neurogenic tumours in the head and neck region.

METHODS

Five neurogenic tumours were analysed with respect to their CT value, the presence of cystic change, target sign, lobulation, connection to the nerve and vascularity.

RESULTS

The contrast-enhanced CT (ECT) of the schwannomas demonstrated either a mass with low enhancement (two out of three cases), which reflected the predominant Antoni B components, or a mass with cystic changes, which was an Antoni A-based schwannoma displaying cystic changes (one out of three cases). On MRI, all tumours showed homogeneous and isointense signals for muscle on T₁ weighted images (T₁ WIs). T₂ weighted images (T₂ WIs) and gadolinium (Gd)-enhanced T₁ WIs demonstrated target sign in both schwannomas. Ultrasound examination showed a well-defined, ovoid or round hypoechoic mass. The direct connection to the nerve was demonstrated in two of the five cases. Lobulation was observed in only one of the five cases and cystic changes were observed in one of the five cases. In all of the cases, no vascularity was seen in power Doppler images (PDIs) obtained percutaneously.

CONCLUSIONS

Low-enhanced areas on ECTs can be specific for schwannomas, which suggests the predominance of Antoni B components. The target sign on T₂ WIs and Gd-enhanced T₁ WIs can be specific, which can be used to differentiate the two different components (Antoni A and Antoni B). The direct connection to the nerve can be a specific finding for neurogenic tumours; however, at present the sensitivity is 40%.

Role of Maxillofacial Surgery in Patients With Neurofibromatosis Type I

Neurofibromas are a clinical manifestation of neurofibromatos is type I (NF1). Management of these tumors remains a challenge for the clinician. The goal of the present study is to point out treatment guidelines for these lesions. Eighteen patients diagnosed with NF1 and presenting lesions of the craniomaxillofacial district were included in the study. On the basis of clinical evidence and patient's expectations, only six patients of this group underwent surgery. All patients that had no surgery were included in a follow-up protocol to evaluate progression of disease. Four patients who underwent surgery had good functional/aesthetic results, whereas two patients had incomplete rehabilitation.

Intraarticular Neurofibroma of the Hip

The magnetic resonance imaging findings in 2 cases of pathologically proven hepatocellular carcinoma that mimicked focal nodular hyperplasia are presented. Both cases were found in patients with cirrhosis, a condition in which focal nodular hyperplasia is unlikely to occur. Recognition that hepatocellular carcinoma may mimic focal nodular hyperplasia in patients with cirrhosis may prevent misdiagnosis and allow for earlier intervention.

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.