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Alan Siu, Michaela Lee, Robert Rice and John S. Myseros

Atypical teratoid/rhabdoid tumors (AT/RTs) are highly malignant CNS tumors found almost exclusively in childhood. Although essentially universally fatal when incompletely resected, prompt diagnosis followed by early chemoradiation can improve outcomes. An AT/RT can occur extraaxially at the cerebellopontine angle (CPA) and cause acute cranial nerve deficits as the presenting sign. The authors report a series of 3 children who presented with isolated acute facial nerve palsies and in whom subsequent diagnosis of a CPA AT/RT was made. The authors propose that in young children whose presenting symptom is an acute facial nerve palsy with a CPA tumor, AT/RT should be highly suspected.

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Andrea Winter, Alan Siu, Aria Jamshidi, Martin Malawer and Jonathan H. Sherman

Spindle cell hemangioendothelioma is a rare benign vascular tumor that is not known to involve the sacrum. The authors describe the case of a 31-year-old woman presenting with low-back and radicular pain without weakness or bowel or bladder dysfunction. Admission CT and MRI studies revealed a large S1–3 lytic sacral lesion. The patient initially underwent a nondiagnostic percutaneous biopsy. She subsequently underwent an open biopsy, during which the lesion was found to be highly vascular. Histological investigation revealed a vasoformative lesion consistent with spindle cell hemangioendothelioma. Preoperative embolization followed by resection via intralesional currettage resulted in resolution of symptoms up to 9 months postintervention. Despite the authors' recommendation, the patient became pregnant at that time and requested no additional follow-up imaging. The authors present the first reported case of a spindle cell hemangioendothelioma of the sacrum and review the current literature.

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Siri Sahib S. Khalsa, Alan Siu, Tiffani A. DeFreitas, Justin M. Cappuzzo, John S. Myseros, Suresh N. Magge, Chima O. Oluigbo and Robert F. Keating


Previous studies have indicated an association of Chiari malformation Type I (CM-I) and a small posterior fossa. Most of these studies have been limited by 2D quantitative methods, and more recent studies utilizing 3D methodologies are time-intensive with manual segmentation. The authors sought to develop a more automated tool to calculate the 3D posterior fossa volume, and correlate its changes after decompression with surgical outcomes.


A semiautomated segmentation program was developed, and used to compare the pre- and postoperative volumes of the posterior cranial fossa (PCF) and the CSF spaces (cisterna magna, prepontine cistern, and fourth ventricle) in a cohort of pediatric patients with CM-I. Volume changes were correlated with postoperative symptomatic improvements in headache, syrinx, tonsillar descent, cervicomedullary kinking, and overall surgical success.


Forty-two pediatric patients were included in this study. The mean percentage increase in PCF volume was significantly greater in patients who showed clinical improvement versus no improvement in headache (5.89% vs 1.54%, p < 0.05) and tonsillar descent (6.52% vs 2.57%, p < 0.05). Overall clinical success was associated with a larger postoperative PCF volume increase (p < 0.05). These clinical improvements were also significantly associated with a larger increase in the volume of the cisterna magna (p < 0.05). The increase in the caudal portion of the posterior fossa volume was also larger in patients who showed improvement in syrinx (6.63% vs 2.58%, p < 0.05) and cervicomedullary kinking (9.24% vs 3.79%, p < 0.05).


A greater increase in the postoperative PCF volume, and specifically an increase in the cisterna magna volume, was associated with a greater likelihood of clinical improvements in headache and tonsillar descent in patients with CM-I. Larger increases in the caudal portion of the posterior fossa volume were also associated with a greater likelihood of improvement in syrinx and cervicomedullary kinking.

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Alan Siu, Gary F. Rogers, John S. Myseros, Siri S. Khalsa, Robert F. Keating and Suresh N. Magge

There is no known correlation between Down syndrome and craniosynostosis. The authors report 2 infants with trisomy 21 and right unilateral coronal craniosynostosis. Both patients were clinically asymptomatic but displayed characteristic craniofacial features associated with each disorder. One patient underwent a bilateral fronto-orbital advancement and the other underwent an endoscopically assisted strip craniectomy with postoperative helmet therapy. Both patients demonstrated good cosmesis at follow-up.

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Matthew T. Stib, Michael Johnson, Alan Siu, M. Isabel Almira-Suarez, Zachary Litvack, Ameet Singh and Jonathan H. Sherman

The authors describe the case of a large WHO Grade III anaplastic oligoastrocytoma extending through the anterior skull base and into the right nasal cavity and sinuses. Glial neoplasms are typically confined to the intracranial compartment within the brain parenchyma and rarely extend into the nasal cavity without prior surgical or radiation therapy. This 42-year-old woman presented with progressive headaches and sinus congestion. MR imaging findings revealed a large intracranial lesion with intranasal extension. Endoscopic nasal biopsy revealed pathology consistent with an infiltrating glioma. The patient subsequently underwent a combined transcranial/endonasal endoscopic approach for resection of this lesion. Pathological diagnosis revealed a WHO Grade III oligoastrocytoma. This report reviews the mechanisms of extradural glioma extension. To the authors' knowledge, it is the second report of a high-grade glioma exhibiting nasal extension without prior surgical or radiation treatment.