Gliosarcoma: Neuroimaging and Immunohistochemical Findings.

BACKGROUND AND PURPOSE: Gliosarcoma (GSC) is an intra-axial lesion which often abuts a dural margin and is composed of glial and mesenchymal elements. This lesion is considered a variant of isocitrate dehydrogenase (IDH)-wild type glioblastoma (GBM). The purpose of this study is to evaluate the imaging and molecular features of GSC in a large patient cohort. METHODS: Pathology-proved GSC cases were collected from our quaternary care center spanning the last 16 years and IDH status was documented. Older GSC cases without prior immunohistochemical testing underwent tissue block staining to obtain IDH status. When available, p53, phosphate and tensin (PTEN), MIB-1, EGFR amplification, and MGMT methylation were recorded and imaging findings tabulated. Logistic regression analyses were performed to determine correlation of molecular markers and imaging characteristics. RESULTS: A total of 25 cases were identified (21 de novo, 4 post-treatment). All lesions contacted a dural, pial, or ependymal surface and were negative for an IDH R132H mutation, including postradiation GSC. In total, 16 of 16 cases showed nonamplification of EGFR/CEP7, 2 of 16 demonstrated MGMT methylation, and multiple lesions demonstrated p53 and PTEN mutations. Imaging features included areas of nodular thickening in necrotic lesions which appeared to abut the site of dural contact. There was no significant correlation of molecular markers with imaging characteristics. CONCLUSION: GSC was IDH(-) in all cases, supporting the current understanding of this lesion being a wild-type GBM variant. Additional molecular markers demonstrated no significant correlation with imaging findings in this cohort.

Scalp Arteriovenous Malformation with Concomitant, Flow-Dependent Malformation and Aneurysm.

BACKGROUND: Scalp arteriovenous malformations (sAVMs) are well-described congenital abnormalities for which co-occurrence with other vascular pathologies significantly alters management strategies. The authors describe a case in which congenital sAVM was found with concomitant intracranial, flow-dependent vascular malformation and schizencephalic developmental anomaly. CASE DESCRIPTION: A 21-year-old man presented with a right-sided bruit and an enlarging palpable, pulsatile scalp mass. Magnetic resonance imaging demonstrated a 5-cm right sAVM and an azygos anterior cerebral artery (ACA) feeding a 2-cm parafalcine vascular anomaly, as well as an unruptured 3-mm, flow-related, distal ACA aneurysm. sAVM feeders were catheterized and embolized with Onyx 18. During resection of the right frontal scalp lesion, dissection below the pericranium was developed to expose the low-flow extracranial sAVM. A supratrochlear arterial feeder and the vascular nidus were coagulated, but radical resection was avoided to prevent scalp necrosis. An anterior right frontal parasagittal craniotomy and dural opening were performed. A developmental anomaly of the right superior frontal gyrus was noted, and a dense vascular network within the anterior parafalcine fold was excised and coagulated. The distal ACA aneurysm was cauterized and wrapped to preserve the parent artery. The patient made an excellent recovery without neurologic deficits. CONCLUSIONS: A review of the literature demonstrated a variety of endovascular and open surgical treatments with limited consensus on standard care. While sAVMs have been described in the literature, the combination of the diverse conditions seen in this case is unique.

Pituitary macroadenomas with oculomotor cistern extension and tracking: implications for surgical management.

OBJECT Oculomotor cistern extension of pituitary adenomas is an overlooked feature within the literature. In this study, 7 cases of pituitary macroadenoma with oculomotor cistern extension and tracking are highlighted, and the implications of surgical and medical management are discussed. METHODS The records of patients diagnosed with pituitary macroadenomas who underwent resection and in whom preoperative pituitary protocol MRI scans were available for review were retrospectively reviewed. The patient and tumor characteristics were reviewed along with the operative outcomes and complications. RESULTS Seven patients (4.1%) with oculomotor cistern extension and tracking were identified in a cohort of 170 patients with pituitary macroadenoma. The most common presenting symptoms were visual deficit (6 patients; 86%), apoplexy (3 patients; 43%), and oculomotor nerve palsy (3 patients; 43%). Lone oculomotor nerve palsy was seen in 2 patients without apoplexy and 1 patient with an apoplectic event. Gross-total resection was achieved via a microscopic endonasal transsphenoidal approach with or without endoscopic aid to the sella in 14%, near-total resection in 29%, and subtotal resection in 57% of patients in the data set. CONCLUSIONS Pituitary adenoma extension along the oculomotor cistern is uncommon; however, preoperatively recognizing such extension should play an important role in the surgeon's operative considerations and postoperative clinical management because this extension can limit gross-total resection using the transsphenoidal approach alone.

Peritumoral cysts associated with pituitary macroadenoma.

OBJECT: Peritumoral cysts are benign nonneoplastic cysts that are found adjacent to extraaxial brain tumors such as meningiomas, schwannomas, craniopharyngiomas, and esthesioneuroblastomas. Peritumoral cysts associated with pituitary macroadenomas have not been previously described in the literature. The authors report 6 cases of giant macroadenoma-associated peritumoral cysts and delineate their imaging spectrum. METHODS: The authors retrospectively reviewed the records of 179 patients diagnosed with pituitary macroadenomas who underwent tumor resection at their institution and had preoperative MRI scans available for review. The patients were evaluated for the presence of associated peritumoral cysts. Clinical presentation, histopathology, follow-up time, tumor and peritumoral cyst dimensions were recorded. Signal intensity on T1-weighted, T2-weighted, diffusion-weighted, and FLAIR sequences, as well as pre- and postcontrast appearance, were determined. RESULTS: Six patients (3.4%) with associated peritumoral cysts were identified in our cohort of 179 patients with pituitary macroadenoma. Twelve patients in the cohort had giant macroadenomas (≥ 4.0 cm), and 50% of these tumors had associated peritumoral cysts with significant extrasellar extension of the macroadenoma. Only tumors with craniocaudal, transverse, and anteroposterior diameters of 3.6 × 3.4 × 4.2 cm to 7.0 × 7.4 × 6.8 cm (mean 5.3 × 5.1 × 5.6 cm), respectively, had associated peritumoral cysts. The growth pattern in all tumors was suprasellar, with predominant anterior and lateral extension. Cysts showed T1-weighted, T2-weighted, and FLAIR hyperintensity in 67%, 67%, and 60% of patients, respectively. There was no contrast enhancement of the cyst wall or fluid contents in any patient. Postoperatively, cysts had completely resolved (4 of 5) or significantly decreased in size (1 of 5). One patient was lost to follow-up. CONCLUSIONS: Macroadenoma-associated peritumoral cysts are rare, benign, and likely nonneoplastic fluid collections that do not represent neoplasm. These cysts display a predictable pattern of hyperintensity on T1-weighted, T2-weighted, and FLAIR sequences and do not enhance. They most likely represent proteinaceous CSF in a sulcus or cistern that becomes trapped (encysted) by anterolateral extension of unusually large macroadenomas. Peritumoral cysts may facilitate resection of the associated macroadenoma by providing a cleavage plane.

Giant ecchordosis physaliphora in an adolescent girl: case report.

The authors describe a rare case of giant ecchordosis physaliphora (EP) in a 16-year-old female patient who presented with diplopia. Magnetic resonance imaging of the brain with Gd contrast revealed a 3.0 × 1.7 × 1.8-cm nonenhancing, extraaxial epidural mass along the dorsal aspect of the clivus that was T2 hyperintense and T1 isointense with intermediate signal on diffusion sequences. Resection via a transnasal transsphenoidal approach to the ventral clival wall resulted in a stable tumor size with no evidence of interval growth after 30 months. Although this case features a strictly extradural EP, this tumor more commonly occurs in the subdural space and requires differentiation from intradural chordoma. Unlike EP, intradural chordoma may enhance with Gd contrast, is more likely to be associated with cranial nerve palsies and brainstem symptoms, and will occasionally have an elevated MIB-1 index. In this paper the authors highlight the different possible midline locations for both EP and chordoma, the difficulty in distinguishing between intradural giant EP and intradural chordoma, and the potential occurrence of these lesions in young people despite their typically slow rate of growth, while also underscoring the need for further investigation into the tumors' cytogenetic behavior.

Masses and malformations of the third ventricle: normal anatomic relationships and differential diagnoses.

The third ventricle lies in the center of the brain. It is surrounded by critical nuclear structures (the hypothalamus and thalami) and important glandular structures (the pituitary and pineal glands). Although a wide array of pathologic processes may involve the third ventricle, most are extrinsic masses. By understanding the anatomic boundaries of the third ventricle and its relationship to adjacent structures, it is possible to create short lists of differential diagnoses. Third ventricle masses can be classified as arising in or immediately adjacent to one of five locations: anterior, posterior, inferior, foramen of Monro, and intraventricular. Anterior masses involve the optic and infundibular recesses, posterior masses affect or arise in the posterior commissure and pineal gland, and inferior masses involve or affect the ventricle floor. Masses may also arise at or adjacent to the foramen of Monro or entirely within the third ventricle. Of the intraventricular masses, chordoid glioma-a rare low-grade primary neoplasm-is unique to the third ventricle. Congenital malformations of the third ventricle are uncommon and are most often noted during childhood. Most commonly, these anomalies represent malformations of the neurohypophysis, which may manifest as hormonal abnormalities, or stenosis of the aqueduct of Sylvius, which manifests as dilatation of the third and lateral ventricles (hydrocephalus).

Magnetic resonance imaging spectrum of medulloblastoma.

INTRODUCTION: Two medulloblastoma variants were recently added to the WHO classification of CNS tumours. We retrospectively analysed the imaging findings of 37 classic and 27 cases of variant medulloblastomas to identify imaging characteristics that might suggest a particular MB subtype. METHODS: Sixty-four patients from three institutions were included. Location, tumour margins, signal intensities on conventional MRI, enhancement pattern, the presence of haemorrhage, calcifications and hydrocephalus were recorded and analysed. Signal characteristics on diffusion-weighted MR images and MR spectra were evaluated when available. RESULTS: Thirty-seven classic type of MB (CMB), twelve cases of desmoplastic/nodular medulloblastoma (DMB), nine medulloblastomas with extensive nodularity (MB-EN), five cases of anaplastic and one of large-cell medulloblastoma were included. Fifty of 64 tumours were located in the 4th ventricle region. On T2WI, CMB were all hyperintense, whereas DMB and MB-EN showed isointensity in up to 66%. One third of the classic MB showed only subtle marginal or linear enhancement. All medulloblastoma variants showed marked enhancement. CONCLUSION: The results of our study suggest: (a) an age-dependent distribution of MB variants, with DMB and MB-EN more common in younger children; (b) a female predominance in DMB; (c) a more common off-midline location in DMB (50%) and MB-EN (33%) variants.

Capillary telangiectasias: clinical, radiographic, and histopathological features. Clinical article.

OBJECT: Brain capillary telangiectasias (BCTs) are small, clinically benign, angiographically occult lesions that are usually incidental findings. Large capillary telangiectasias have not been reported previously as most BCTs are very small. Symptomatic BCTs are also rare, with few reports in the literature. The authors review the clinical manifestations, imaging, and histopathological characteristics of BCTs to further elucidate the diagnostic and clinical features of these vascular malformations. METHODS: The authors completed a retrospective radiological review of all cases of BCTs in the neuroradiology database at the University of Utah involving patients treated between January 1993 and December 2007. The MR imaging scans were reviewed, and the BCT was measured in 2 dimensions. They arbitrarily chose > 1 cm to define a large BCT as a majority of these lesions were smaller than that. The medical chart and the electronic database were used to gather each patient's clinical information. RESULTS: One hundred thirty patients were identified in the archived neuroradiology database of capillary telangiectasias. Cases involving 105 patients with definite capillary telangiectasias were reviewed, and from these, 7 patients were identified to have a large capillary telangiectasia measuring > 1 cm. Upon further review, 2 of these patients were identified as having symptoms likely related to their capillary telangiectasia. These 2 cases are reported in the article. No patients with smaller BCTs were found to have symptoms related to their lesion. CONCLUSIONS: Brain capillary telangiectasias are small vascular malformations that rarely cause symptoms. They are often overlooked on imaging because of their clinically benign nature; however, they have been misdiagnosed as glial tumors in the past. Specific MR imaging sequences (T1-weighted postcontrast and gradient refocused echo) are valuable in aiding diagnosis, as histopathological diagnosis is often not possible. These cases highlight that BCTs can cause symptoms, a finding that may actually be related to the size of the lesion (28.6% of large BCTs in this series were symptomatic, whereas none of the small ones were).

Hemorrhagic and nonhemorrhagic Rathke cleft cysts mimicking pituitary apoplexy.

OBJECTIVES: Rathke cleft cysts (RCCs) are infrequently symptomatic, and apoplexy is one of the most unusual presentations. Only a few cases of apoplexy associated with RCCs have been reported, and their clinical, imaging, surgical, and pathological features are poorly understood. In the cases that have been reported, intracystic hemorrhage has been a consistent finding. The authors report 6 cases of RCCs in which the presenting clinical and imaging features indicated pituitary apoplexy, both with and without intracystic hemorrhage. METHODS: The authors retrospectively reviewed charts and magnetic resonance (MR) imaging studies obtained in patients who underwent transsphenoidal surgery for RCC. Six patients were identified who presented with symptoms and MR imaging characteristics consistent with pituitary apoplexy but were found intraoperatively to have an RCC. All 6 patients presented with a sudden headache, 2 with visual loss, and 1 with diplopia. Review of the preoperative MR images demonstrated mixed signal intensities in the sellar masses suggestive of a hemorrhagic pituitary tumor. In all patients there was a presumed clinical diagnosis of pituitary tumor apoplexy and an imaging-documented diagnosis of hemorrhagic pituitary tumor. RESULTS: All 6 patients underwent transsphenoidal resection to treat the suspected pituitary apoplexy. Intraoperative and histopathological findings were consistent with the diagnosis of an RCC in all cases. Only 2 cases showed evidence of hemorrhage intraoperatively. In all cases, an intracystic nodule was found within the RCC at surgery, and this intracystic nodule was present on the initial MR imaging when retrospectively reviewed. The imaging characteristics of the intracystic nodules were similar to those of acute hemorrhage seen in cases of pituitary apoplexy. CONCLUSIONS: The clinical and imaging features of RCCs appear similar to those of hemorrhagic pituitary tumors, making them often indistinguishable from pituitary apoplexy.

Anatomic and pathologic spectrum of pituitary infundibulum lesions.

OBJECTIVE: The pathologic spectrum of pituitary infundibulum disease is diverse. We reviewed 65 infundibular lesions in 44 adult and 21 pediatric patients and summarized their imaging features and clinical presentation. CONCLUSION: The spectrum of pathology involving the pituitary infundibulum is broad yet distinct from other pathology in the sella and parasellar region. Pituitary stalk lesions can be grouped into three categories: congenital and developmental, inflammatory and infectious, and neoplastic. Knowledge of the imaging appearance of diseases specific to adults and to children is important for accurate diagnosis and treatment.

Neuroradiologic characteristics of astroblastoma.

INTRODUCTION: Astroblastoma is a rare glial tumor of uncertain origin. Only a few scattered case reports and one small case series have described the radiologic appearance of this uncommon tumor. Many features previously identified are similar to those of other primary malignant brain tumors. We report the largest imaging series to date and further delineate the CT and MRI features of astroblastoma. We identify those features that may be useful in distinguishing astroblastoma from other neoplasms. METHODS: The radiologic images, pathology reports, and clinical information of 12 patients with pathology-confirmed astroblastoma were retrospectively reviewed. CT and MRI findings including location, morphology, signal intensity, and presence and patterns of enhancement were tabulated. RESULTS: Patients ranged in age from 0 (newborn) to 50 years with a mean of 20 years at the time of initial diagnosis. A striking female preponderance (11:1) was found. All tumors were supratentorial. There were multiple intratumoral cysts in 7 (58%) of the 12 patients. Nine (75%) showed strong rim enhancement and 3 (25%) showed no rim enhancement. CONCLUSION: The imaging features of astroblastoma are identified in 12 previously unreported cases. Distinguishing features that can be used to narrow the differential diagnosis with more common primary brain neoplasms reflect a combination of age, anatomic location, and specific imaging findings such as demarcation, heterogeneous tumor enhancement, rim enhancement, and a multicystic "bubbly" appearance. Intraventricular location, intratumoral hemorrhage with a fluid-fluid level, and dural "tails" are less common but important additions to the imaging spectrum.

Intracranial cysts: radiologic-pathologic correlation and imaging approach.

Cysts and cystic-appearing intracranial masses have a broad imaging and pathologic spectra. The authors review the pathologic findings, origin, radiologic appearance, and differential diagnosis of many different intracranial cysts. A diagnostic algorithm based on most common anatomic locations is presented that helps narrow the differential diagnosis.

Subependymomas: an analysis of clinical and imaging features.

OBJECTIVE: Subependymomas are slow-growing, benign tumors usually found incidentally in the fourth ventricle at autopsy. They are typically associated with the ventricular system and become apparent clinically only when symptoms of hydrocephalus or mass effect develop. We review clinical, histological, and contemporary radiographic presentations of 16 subependymomas, including 2 intraparenchymal tumors. METHODS: We retrospectively evaluated eight patients with pathologically proven subependymomas. Initial magnetic resonance imaging and magnetic resonance spectroscopy were reviewed when available. Imaging was also available on eight outside subependymoma cases reviewed by our radiology department. RESULTS: Twelve of these subependymomas were intraventricular, one was in the posterior fossa, two were intraparenchymal, and one was an intramedullary spinal cord tumor. These lesions were hypo- to hyperintense on T1- and T2-weighted magnetic resonance imaging, with minimal to moderate enhancement. Initial complaints included headache, seizures, tingling sensations, and weakness. Among our eight patients who underwent gross total resection with no adjuvant therapy, no recurrences have been noted on follow-up magnetic resonance imaging. CONCLUSION: Subependymomas are rare, representing only 0.51% of all central nervous system tumors operated on during an 8-year period at the University of Utah. Clinical symptoms were associated with tumor location: intracranial masses caused headaches, seizures, and neurological complaints, and spinal cord locations resulted in neurological deficit. The authors review the clinical presentation, management, and contemporary radiographic appearance of this rare tumor.