Intracranial Primary Mesenchymal Chondrosarcoma: A Case Report

We report a case of dural-based intracranial primary mesenchymal chondrosarcoma, initially thought to be a meningioma. This rare tumor should be included in the differential diagnosis of an aggresive dural-based lesion occurring in a young adult. A 27-year-old man presented with headache, nausea and vomiting, first experienced months earlier. Pre-enhanced CT revealed the presence of a well-marginated isodense mass with dense calcifications in the frontoparietal convexity, while MR images depicted a lobulated extra-axial mass with peritumoral edema. At T1-weighted imaging, the signal intensity of the mass was slightly low or than that of gray matter, while T2-weighted imaging demonstrated heterogeneous high signal intensity. Some portions of the tumor showed low signal intesnity at all sequences, suggesting the presence of calcification. After the injection of contrast medium, heterogeneous enhancement was observed. We report the radiologic findings of an intracranial primary mesenchymal chondrosarcoma, confirmed pathologically.

Congenital Glioblastoma Multiforme: A Case Report

Congenital glioblastoma multiforme is relatively rare accounting for 2-9% of all congenital brain tumors. We deseribe a case of congenital glioblastoma multiforme which occurred in the lateral ventricle. T1-weighted images revealed high signal intensity, with areas of internal low signal intensity, while T2-weighted images showed low signal intensity with focal internal high-signal portions. Post-contrast T1-weighted images depicted a lateral ventricular mass which extended to adjacent brain parenchyme and had a serpentine signal void representing internal vessel.

CT, MR and Angiographic Findings of Hemangiopericytomas

PURPOSE: Hemangiopericytoma(HP) exhibits its pathologic findings different from those of meningioma or oth-erangiomatous tumor; and its clinical behavior is unique and prognosis worse than other cases. We reviewed the CT,MR and angiographic findings of HPs and evaluated differential radiologic points of comparison be-tween typicalmeningiomas and meningeal HPs. MATERIALS AND METHODS: MR(n=16), CT(n=5) and angiographic imaging(n=10) wereperformed in 18 pa-tients(M:F=12:6, mean age:45 years) with histologically proven primary HPs. We evaluated theimaging find-ings of HPs with respect to site, shape, size, signal intensity, enhancement characteristics,vascular signal voids, calcification, bony and adjacent sinus involvement, and angiographic findings. RESULTS:HPs were meningeal in 14 cases and nonmeningeal in four. Meningeal HPs were located in the parasagittalregion(n=8), convexity(n=3), intradural extramedullary space(n=1), choroid plexus(n=1), and ol-factorygroove(n=1). Nonmeningeal HPs were located in the masticator space(n=2), paraspinal area(n=1) and supraclaviculararea(n=1). The mean maximal dimension of tumors was about 5.4cm and their shape was papillary(n=8) orlobulated(n=7). MR images showed high(n=13) or iso(n=3) signal intensities on T2WI, and heterogeneity onT2WI(n=9). Vascular signal voids in the mass were seen in all cases, while in two cases, CT scanning showednodular dense calcification. Bone destruction was present in six cases, but no hyperostosis was found. In fivecases, the superior sagittal sinus was involved. Angiographic images revealed highly vascu-lar masses supplied bythe internal carotid artery(n=5), external carotid artery(n=8), descending scapular artery(n=1) andradiculomedullary artery(n=1), with delayed tumor blush during the capillary and venous phase in which there wasno arteriovenous shunt. CONCLUSION: HP is one of the extra-axial tumors in which there is hypervascularity,aggressive bony destruc-tion arising in the meningeal and extrameningeal area, and heterogeneous high signalintensity, as seen on T2WI. Calcification is rare.

Intracranial Angiolipoma: A Case Report

Intracranial angiolipoma is extremely rare. We report the radiologic findings of angiolipoma in the rightmiddle cranial fossa, extending medially into the suprasellar and cavernous sinus region, in a 63-year-old woman.The lesion was a relatively well marginated extra-axial tumor that showed low density on precontrast CT and markedenhancement after contrast infusion. MR imaging showed heterogeneous low signal on T1W1 mixed with hyperintensefoci on T2W1, and marked enhancement after gadolinium infusion. On cerebral angiography, displacement of the rightinternal carotid artery by the tumor was seen. On an arteriogram of the right external carotid artery, the massshowed persistent capillary blush.

Solitary Hemorrhagic Brain Metastasis from Pulmonary Blastoma: A Case Report

Pulmonary blastoma is a rare primary lung malignancy consisting of mesenchymal and epithelial components resembling the fetal lung. We report a case of pulmonary blastoma with solitary hemorrhagic brain metastasis in a 32-year-old man. This metastatic lesion was composed mainly of hemorrhagic high density and central necrotic low density areas; on CT it showed partial contrast enhancement and was thus impossible to distinguish from other hemorrhagic lesions.

Imaging Findings of Pediatric Oligodendroglioma

PURPOSE: The purpose of this study is to describe the imaging characteristics of oligodendroglioma in childhood. MATERIALS AND METHODS: Eight CT scans and 12 MR images were retrospectively reviewed in 12 children (mean age, 9.5 years) with pathologically-proven oligodendroglioma. The most frequent symptoms were seizure and headache, with a mean duration before diagnosis of 21 months. Location, MR signal intensity, calcification,intratumoral hemorrhage, cystic change, peritumoral edema and contrast enhancement were retrospectively analyzed. RESULTS: The supratentorial location was most frequent (9/12, 75%) and the majority of tumors were located peripherally or subcortically (7/9, 78%). On MR, most tumors demonstrated low signal intensity on T1WI and high signal intensity on T2WI ; cystic change was frequent (10/12, 83%). Tumor enhancement was seen in 60% of cases (6/10), with various enhancement patterns. Intratumoral hemorrhage was seen in two cases. On CT, the tumors were usually hypodense and calcification was noted in two cases (2/8, 25%). Peritumoral edema and mass effect of the tumor were seen in five (5/12,42%). Hydrocephalus was associated in two cases. CONCLUSION: In childhood, most oligodendrogliomas demonstrate a peripherally located supratentorial mass, with frequent cystic change. Calcification or intratumoral hemorrhage were less frequent than in previously reported adult series.

CT and MRI Findings of Intraventricular Neurocytoma

PURPOSE: Intraventricular neurocytoma, a recently recognized benign primary cerebral tumor of young adults, can be confused with oligodendroglioma and other neoplasms. The purpose of this paper is to describe the characteristic CT and MR imaging findings of intraventricular neurocytoma. MATERIALS AND METHODS: CT and MR imaging findings of five patients (M:F=2:3, ages 17-64, mean age 41) with intraventricular neurocytoma were retrospectively reviewed. All patients underwent CT scan and cerebral angiography. In four patients, MR imaging was performed and axial, sagittal, and coronal T1- and T2-weighted spin echo and gadolinium enhanced images were obtained. We evaluated the tumors with regard to location, size, shape, CT density, MR intensity, enhancement pattern, and internal texture such as calcification and cystic changes. RESULTS: All tumors were located in the lateral ventricles; especially around the foramen of monro (four cases). Their size varied from 1.0 x 1.5 cm to 4.0 x 3.0 cm and all showed a lobulated appearance. On precontrast CT scan, all tumors showed heterogeneous density due to multiple intratumoral calcifications and cystic changes. MR imaging showed a heterogeneous signal with iso- or slight hyperintensity on T1-weighted and hyperintensity on T2-weighted image, relative to cerebral parenchyme. After contrast injection, varying degrees of enhancement were noted on both CT and MR images. CONCLUSION: An intraventricular mass with or without calcification and cystic changes in the anterior portion of the lateral ventricle is suggestive of intraventricular neurocytoma. MR imaging is better in defining the exact location and cystic changes of the tumor, whereas CT is better for the characterization of calcifications.

Differential Diagnosis of the 4th Ventricular Tumors

PURPOSE: To determine by analysis of MR and CT findings the points of differentiation among 4th ventricular tumors, especially the change of shape of the 4th ventricle caused by the site at which 4th ventricular tumors originate. MATERIALS AND METHODS: The authors retrospectively analyzed and compared the CT(n=5) and MRI(n=12) findings of 13 pathologically proven 4th ventricular tumors comprising six medulloblastomas three ependymomas (4 cases) and three choroid plexus papillomas. RESULTS: On axial MRI medulloblastomas showed anterior and anterolateral CSF-clefts between the tumor mass and the 4th ventricular wall in one and five cases, respectivaly ; on sagittal MRI, anterior beaking of the upper 4th ventricle was seen. Two ependymomas showed posterolateral CSF-cleft on axial MRI and posterior beaking of the upper 4th ventricle on sagittal MRI. Two ependymomas and all choroid plexus papillomas showed anterior, posterior and lateral CSF-clefts on axial MRI, and anterior and posterior beakings of upper 4th ventricle on sagittal MRI. On Gd-DTPA enhanced T1WI, all medulloblastomas and ependymomas showed inhomogeneous enhancement, and all choroid plexus papillomas showed homogeneous enhancement. On CT, tow choroid plexus papillomas showed dense calcifications. CONCLUSION: The differential diagnosis of 4th ventricular tumors can be preoperatively suggested by analysis of findings such as a CSF-cleft between the tumor mass and the 4th ventricular wall on axial MR and CT images, the shape of the upper 4th ventricle on sagittal MRI, contrast enhancement pattern, necrosis and cyst, and CSF seeding.