MRI findings of primary intracranial sarcomas in children.

BACKGROUND: Primary intracranial sarcoma is a very rare high-grade tumor. Scant reports exist on this malignancy in children, which limit the information about its imaging characteristics. OBJECTIVE: We aimed to describe the main characteristics of primary intracranial sarcoma on MRI. MATERIALS AND METHODS: In this cross-sectional descriptive observational study, we reviewed 18 patients (aged 1-18 years) with primary intracranial sarcomas diagnosed between 2015 and 2021. RESULTS: The main findings were contrast enhancement (100%), diffusion restriction (78%), hemorrhage (89%), meningeal extension (67%), necrosis (67%), and supratentorial location (72%). CONCLUSION: Primary intracranial sarcoma are typically supratentorial in location. MRI findings of primary intracranial sarcoma are similar to other intracranial malignancies.

Pre-operative embolization for staged treatment of infantile choroid plexus papilloma.

Choroid plexus papillomas (CPPs) are benign but rare neuroepithelial neoplasms of the choroid plexus that represent the non-malignant form of a spectrum of tumors of the choroid plexus. The vast majority of CPPs present in children under 5 years of age. Some CPPs are diagnosed prenatally, but many of them reach a large size before diagnosis. CPPs typically present with signs and symptoms of hydrocephalus. Treatment of these tumors has traditionally been with surgical resection. Large CPPs in young children present a challenge due to risk of high blood loss during resection. Here, the authors describe the case of a 3-month-old presenting with hydrocephalus and a large CPP of the third ventricle that was managed with a staged strategy of embolization followed by a delayed resection, allowing the tumor to involute prior to surgery.

Neurenteric cyst of the temporal bone: A case report.

Neurenteric cysts are rare, developmental malformations mainly found in the spinal canal. The authors report on a 29-year-old woman who presented with congenital left-sided hearing loss and a 9 days history of left ear pain and facial weakness (House-Brackmann IV). Radiological examination revealed a complex 7 mm cystic structure involving the petrous and mastoid portions of the left temporal bone. Intraoperatively, a red-brown multicystic mass was discovered and excised completely. Histologic findings showed simple columnar epithelium with goblet cells and bilayers of submucosal musculature, resembling normal intestinal linings. Post resection, the patient regained nearly full facial nerve capabilities (House-Brackmann II) with complete resolution of pain, but no changes to her hearing. The objectives of this case report are to describe the clinical, radiologic, intraoperative, and pathologic characteristics of an extradural temporal neurenteric cyst with sensorineural deficits to contribute to the growing knowledge regarding this rare entity.

Safety and efficacy of brainstem biopsy in children and young adults.

OBJECTIVE: Biopsies of brainstem lesions are performed to establish a diagnosis in the setting of an atypical clinical or radiological presentation, or to facilitate molecular studies. A better understanding of the safety and diagnostic yield of brainstem biopsies would help guide appropriate patient selection. METHODS: All patients who underwent biopsy of a brainstem lesion during the period from January 2011 to June 2019 were reviewed. Demographic, radiological, surgical, and outcome data were collected. RESULTS: A total of 58 patients underwent 65 brainstem biopsies during the study period. Overall, the median age was 7.6 years (IQR 3.9-14.2 years). Twenty-two of the 65 biopsies (34%) were open, 42 (65%) were stereotactic, and 1 was endoscopic. In 3 cases (5%), a ventriculoperitoneal shunt was placed, and in 9 cases (14%), a posterior fossa decompression was performed during the same operative session as the biopsy. An intraoperative MRI (iMRI) was performed in 28 cases (43%). In 3 of these cases (11%), the biopsy was off target and additional samples were obtained during the same procedure. New neurological deficits were noted in 5 cases (8%), including sensory deficits, ophthalmoparesis/nystagmus, facial weakness, and hearing loss; these deficits persisted in 2 cases and were transient in 3 cases. A pseudomeningocele occurred in 1 patient; no patients developed a CSF leak or infection. In 8 cases (13%) an additional procedure was needed to obtain a diagnosis. CONCLUSIONS: Brainstem biopsies are safe and effective. Target selection and approach should be a collaborative effort. iMRI can be used to assess biopsy accuracy in real time, thereby allowing any adjustment if necessary.

Evaluation and treatment of children with radiation-induced cerebral vasculopathy.

OBJECTIVE: Stenoocclusive cerebral vasculopathy is an infrequent delayed complication of ionizing radiation. It has been well described with photon-based radiation therapy but less so following proton-beam radiotherapy. The authors report their recent institutional experience in evaluating and treating children with radiation-induced cerebral vasculopathy. METHODS: Eligible patients were age 21 years or younger who had a history of cranial radiation and subsequently developed vascular narrowing detected by MR arteriography that was significant enough to warrant cerebral angiography, with or without ischemic symptoms. The study period was January 2011 to March 2019. RESULTS: Thirty-one patients met the study inclusion criteria. Their median age was 12 years, and 18 (58%) were male. Proton-beam radiation therapy was used in 20 patients (64.5%) and photon-based radiation therapy was used in 11 patients (35.5%). Patients were most commonly referred for workup as a result of incidental findings on surveillance tumor imaging (n = 23; 74.2%). Proton-beam patients had a shorter median time from radiotherapy to catheter angiography (24.1 months [IQR 16.8-35.4 months]) than patients who underwent photon-based radiation therapy (48.2 months [IQR 26.6-61.1 months]; p = 0.04). Eighteen hemispheres were revascularized in 15 patients. One surgical patient suffered a contralateral hemispheric infarct 2 weeks after revascularization; no child treated medically (aspirin) has had a stroke to date. The median follow-up duration was 29.2 months (IQR 21.8-54.0 months) from the date of the first catheter angiogram to last clinic visit. CONCLUSIONS: All children who receive cranial radiation therapy from any source, particularly if the parasellar region was involved and the child was young at the time of treatment, require close surveillance for the development of vasculopathy. A structured and detailed evaluation is necessary to determine optimal treatment.

Diagnostic Imaging Fundamentals: Brain Vascular Pathology.

INTRODUCTION: This module was created to supplement the traditional learning methods that senior medical students, first-year radiology residents, and residents in other specialties employ to learn the fundamentals of radiologic image interpretation. It is part of an ongoing project entitled Diagnostic Imaging Fundamentals (DIF), with each module covering a unique topic. This module covers brain vascular anatomy, common imaging modalities, and imaging characteristics of brain vascular pathologies. METHODS: This module has been designed for team-based learning and consists of advance-preparation reading material, in-class individual and group readiness assurance tests, and a group application exercise. Students are evaluated both individually and as groups. These DIF modules are designed primarily for group learning and are well suited for the academic setting. RESULTS: The feedback we received from first-year radiology residents was 100% positive, and the most frequent remark used by learners in their comments was "very helpful." Our limited feedback suggests that the level of material is appropriate for trainees at or above their final year of medical school. DISCUSSION: We are confident that this module will benefit students and residents who are eager to learn the fundamentals of brain vascular imaging and will serve as a useful adjunct to traditional methods of learning. We believe the module's application of team-based learning can act as a model for collaborative learning in a traditionally didactic learning environment. Future work will include expanding use of the module to larger groups of radiology residents, medical students, and residents in other specialties.