Aaron Cutler

Primary leptomeningeal medulloblastoma ☆

We report the case of an 8-year-old boy who presented with a 2-month history of headaches and mild visual impairment and was found to have a medulloblastoma with primary leptomeningeal involvement. No mass lesion was found on imaging studies, during subsequent intraoperative surgical inspection or at autopsy. The pathologic findings were first documented on cerebrospinal fluid cytologic examination and biopsy of the cerebellum and were later confirmed at necropsy. To our knowledge, this is the third reported case of medulloblastoma identified with primary leptomeningeal involvement without a cerebellar mass and the first such case with documented autopsy findings.

Critical appraisal of extent of resection of clival lesions using the expanded endoscopic endonasal approach.

Objectives To present a critical evaluation of our experience using an expanded endoscopic endonasal approach (EEEA) to clival lesions and evaluate, based on the location of residual tumor, what the anatomic limitations to the approach are. Design A retrospective review of all endoscopic endonasal operations performed at our institution identified 19 patients with lesions involving the clivus. Extent of resection was determined by preoperative and postoperative tumor volumes. Results Three patients underwent planned subtotal resections. Of the remaining patients, gross total resection was achieved in 8/16 (50%), > 95% in 5/16 (31%), and < 95% in 3/16 (19%). Residual tumor occurred, most commonly with extension posterior and lateral to the internal carotid artery, with inferior, lateral invasion of the occipital condyle and with deep inferior extension to the midportion of the dens. Conclusions The EEEA represents a safe and effective technique for the resection of clival lesions. Despite excellent overall visualization of this region we found that adequate exposure of the most lateral and inferior portions of large tumors is often difficult. Knowledge of these limitations allows us to determine which tumors are best suited for an EEEA and which may be more appropriate for an open skull base or combined technique.

Transsphenoidal endoscopic skull base surgery: state of the art and future perspective

Abstract Given refinements in endoscopic image quality, instrumentation, surgical navigation, skull base closure techniques and anatomical understanding, the endonasal endoscopic approach is now a well-accepted and widely utilized technique for removal of many if not most midline ventral skull base tumors. Pituitary adenomas and Rathke’s cleft cysts (RCCs) constitute the majority of lesions removed via this route; however, craniopharyngiomas, clival chordomas, midline meningiomas and other benign and malignant skull base tumors are now increasingly removed by this approach. Herein we describe the evolution of the endonasal endoscopic technique, its current use for sellar and midline skull base tumors and potential for future innovation.

Transsphenoidal Surgery for Non-Adenomatous Tumors: Effect on Pituitary Function

Pituitary adenomas are the most common intrasellar tumor. However, a wide variety of non-adenomatous lesions also arises in the sellar and parasellar region and can impact pituitary gland function. The lesions most commonly associated with pituitary hormonal disturbance include craniopharyngiomas, Rathke’s cleft cysts, arachnoid cysts and sellar metastases while meningiomas and clival chordomas less commonly affect gland function. Depending on the specific lesion and location, surgical resection can result in improvement or worsening of endocrinopathy. Thorough pre-operative hormonal evaluation, sellar imaging with attention to gland and infundibulum location as well as intra-operative dissection techniques aimed at preserving the hypothalamic-pituitary axis are essential to minimize the risk of new hormonal dysfunction. This chapter discusses the surgical management of these lesions and characterizes the presenting and post-operative pituitary hormonal outcomes related to the specific lesion pathology.