Delayed post-traumatic fronto-ethmoidal sinus mucocele evaluated with short and long TE MR spectroscopy.

Mucoceles are slow-growing, benign, expansile, mucoid-filled masses developing after obstruction of the sinus ostium. Late post-traumatic mucoceles are relatively rare entities and the literature is limited to single case reports. We describe an unusual case of post-traumatic fronto-ethmoidal mucocele, evaluated with computed tomography (CT), magnetic resonance imaging (MRI) and proton MR-spectroscopy ((1)H-MRS). As a contribution to the diagnostic work-up of the mucocele, (1)H-MRS demonstrates a dominant peak at 2.0 ppm at long echo time (TE) and an additional component at 3.8 ppm at short TE due to mucus glycoprotein compounds of the mucocele.

Intramedullary capillary hemangioma associated with hydrocephalus in an infant.

This 3-month-old child presented with an enlarging head circumference arising from communicating hydrocephalus with large subarachnoid spaces in the posterior fossa. Neuroimaging performed to clarify the origin and pathogenesis of the hydrocephalus revealed a vascular lesion within the dorsal spinal cord. Insertion of a cerebrospinal fluid shunt and total removal of the spinal tumor were performed successfully. Histological examination of the medullar lesion demonstrated a capillary hemangioma. Proposed mechanisms for increased intracranial pressure and spinal cord lesions are presented. A spinal hemangioma in this age range associated with hydrocephalus has not been reported previously, but spinal lesions must be considered in the presence of hydrocephalus with no clear origin.

Immunohistochemical and molecular study of radiation-induced multiple meningiomas with pleural and pulmonary metastasis.

In the present study, the telomerase activity and the putative alterations of genes involved in cell-cycle control (p53, Fas and pRb) were investigated in a radiation-induced meningioma with multiple recurrences and pleural-pulmonary metastases (the patient, a 34-year-old male, had a history of carcinoma of the tongue of testicular lymphocytic lymphoma). Expression of VEGF and vasculature pattern were also studied. Expression of VEGF, pRb and p53 were evaluated by immunohistochemistry on formalin-fixed, paraffin-embedded samples of the tumor. VEGFmRNA was determined by competitive PCR. Fas, FasL and hTERT were evaluated by RT-PCR. Telomerase activity was examined by the TRAP assay. An intense vascularization was observed, supported by high expression of VEGFmRNA (isoforms 121 and 165). pRb and p53 were overexpressed. Fas was undetectable with PCR, whereas FasL was positive. Furthermore, the lesion showed an elevated telomerase activity (TPG, 22), according to the high expression of hTERT. These findings emphasized that even among generally benign neoplasms, such as meningiomas, some highly malignant tumors may develop, as in our case, in which several mechanisms were activated in the cancer progression to guarantee the immortalization of cellular clones (angiogenic phenomenon, activation of telomerase and of anti-apoptotic mechanisms) and the blood spread. Thus, the data illustrate the importance of searching for genetic aberrations (which are a hallmark of malignancy) in meningiomas, as predictive and reliable factors of the possibility to recur and to metastasize.

The role of somatostatin in vasogenic meningioma associated brain edema.

Many tumors, including meningiomas, express somatostatin receptors, suggesting the application of somatostatin analogues for therapy and diagnosis. Sixty percent of meningiomas are associated with perilesional edema, whose development seems to be related to the vascular endothelial growth factor, although it requires an efficient pial blood supply. However, in several neoplastic models, other mediators seem to cooperate with vascular endothelial growth factor in regulating angiogenesis. We evaluated somatostatin receptors (sst2) in relation to the possibility that somatostatin analogues may influence vascular endothelial growth factor production with reduction of edema. Of 35 studied meningiomas, 21 presented peritumoural edema. Vascular endothelial growth factor, microvascular density and pial blood supply were significantly related to the edema (P = 0.0001, P = 0.0001, P = 0.0005). Similarly, a relation was found between sst2 and microvascular density (r = 0.58, P < 0.001) and between sst2 and vascular endothelial growth factor expression (P = 0.03). This suggests that somatostatin analogues may be relevant for the treatment of meningiomas.

Contrast-enhanced three-dimensional magnetic resonance angiography of atherosclerotic internal carotid stenosis as the noninvasive imaging modality in revascularization decision making.

BACKGROUND AND PURPOSE: In patients with severe internal carotid artery stenoses, thromboendarterectomy significantly reduces both ischemic stroke and the risk of more ischemic attacks. Digital subtraction angiography (DSA) is the accepted preoperative test to determine whether a high-grade stenosis is present and requires surgical therapy. However, DSA has a procedural risk of stroke between 0.7% and 1%. An accurate, noninvasive imaging protocol with no risk of severe complications would significantly increase the benefit of surgical treatment. The aims of the study were (1) to evaluate the diagnostic accuracy of contrast-enhanced magnetic resonance angiography (CEMRA) in detecting and grading internal carotid artery stenoses and (2) to assess the misclassification rate of vessels suitable for revascularization by CEMRA. METHODS: Ninety-two patients with sonographic evidence of neck vessel stenosis were enrolled in the study. All patients were submitted to CEMRA and DSA. CEMRA images were evaluated for the presence of mild, moderate, or severe stenosis and occlusion. RESULTS: Sensitivity, specificity, and diagnostic accuracy were 97%, 82%, and 92.5%, respectively. Agreement with DSA was optimal at kappa=0.87. The misclassification rate of CEMRA was 3.1% because of its tendency to overestimate the stenosis. CONCLUSIONS: The high diagnostic accuracy and limited misclassification rate suggest that CEMRA can be considered a powerful tool for the preoperative, noninvasive evaluation of atherosclerotic pathology of carotid arteries.