Elsevier

World Neurosurgery

Volume 118, October 2018, Pages e346-e355
World Neurosurgery

Original Article
Imaging-Ambiguous Lesions of Meckel's Cave—Utility of Endoscopic Endonasal Transpterygoid Biopsy

https://doi.org/10.1016/j.wneu.2018.06.190Get rights and content

Highlights

  • A variety of lesions can be predominantly isolated to Meckel's cave.

  • Meckel's cave lesions require biopsy for diagnosis and treatment selection.

  • The endoscopic transpterygoid approach provides direct and minimally invasive access.

  • The endoscopic transpterygoid biopsy is safe, efficient, and efficacious.

Introduction

Meckel's cave is a dural-lined cavity in the middle fossa skull base in which lies the Gasserian ganglion, a potential site for tumors and inflammatory lesions. A variety of lesions can be predominantly isolated to Meckel's cave, including extension from head and neck cancers, other malignant tumors, as well as benign lesions. Clinical presentation and imaging findings are often insufficient to establish a diagnosis. Hence, histologic confirmation is required to determine the appropriate treatment strategy. Several surgical approaches have been used to reach this deep-seated area, often with significant morbidity and prolonged recovery. Given advancements in endoscopy and greater facility with the technique, the endoscopic endonasal approach has been used increasingly to reach lesions in the region.

Methods

A single-institution, retrospective chart review over a 10-year period was performed to identify and describe patients with pathologically differing but imaging-similar lesions with their epicenter in Meckel's cave.

Results

Of a total of 21 cases of lesions in Meckel's cave approached by an endoscopic endonasal transpterygoid approach, we present 6 patients with imaging-ambiguous lesions involving Meckel's cave that were biopsied via the extended endoscopic endonasal approach. Among this diverse group, pathology included B-cell lymphoma, squamous cell carcinoma, adenocarcinoma, malignant schwannoma, benign schwannoma, and neurosarcoidosis.

Conclusions

We explore not only the relevance of this approach in the armamentarium of the modern skull-base surgeon but also its limitations and conclude that the endoscopic endonasal approach provides a safe and relatively direct, minimally invasive corridor to many lesions of Meckel's cave.

Introduction

Meckel's cave is a dural cavity in the middle cranial fossa near the petrous apex. It is inferolateral to the cavernous sinus and abducens nerve and superolateral to the petrous and vertical segments of the internal carotid artery. It is formed by 2 layers of dura that envelop the trigeminal or Gasserian ganglion and major portions of the proximal trigeminal nerve.1, 2, 3 Its deep-seated location and surrounding critical neurovascular structures allows it to serve as a haven for contiguous neoplasms and those that have traveled via perineural spread.4, 5

Various benign and malignant tumors, as well as vascular and inflammatory processes, can involve Meckel's cave.6, 7, 8 It is often difficult to establish a definitive diagnosis of a Meckel's cave lesion based on clinical findings and imaging characteristics alone because of the multitude of pathologies that can be found in the region and because these lesions often resemble one another. In most cases, a biopsy or resection is indicated, not only to establish a diagnosis and pursue additional treatment, but also for neural decompression, providing symptomatic relief.5

Several surgical approaches have been described to access lesions in Meckel's cave. These techniques traditionally have included open skull-base approaches, such as the transpetrosal and retrosigmoid approaches, as well as a percutaneous biopsy approach.3, 7, 8, 9, 10 More recently, the endoscopic endonasal approach has been proposed as a viable option in accessing Meckel's cave lesions. As first described by Kassam et al.8 in 2009, working directly through the nasal cavity, the maxillary sinus, and pterygopalatine fossa, the lateral sphenoid region and anterior border of Meckel's cave can be reached without brain manipulation or retraction, providing excellent access to lesions is this area.7, 8, 11, 12, 13

In this series, we describe 5 patients with isolated Meckel's cave lesions and 1 with predominant Meckel's cave involvement and some cavernous sinus invasion, including 4 with perineural invasion and extension along the trigeminal nerve branches. An endoscopic endonasal approach to Meckel's cave was performed in all the cases to determine the histopathologic diagnosis and optimal treatment options. Herein, we describe the clinical scenarios, surgical approach, and its limitations that demonstrate the value and facility of the technique as a minimally invasive alternative to open lateral and posterior skull-base approaches.

Section snippets

Case Presentations

We retrospectively reviewed the charts of patients who underwent endoscopic endonasal approaches for skull-base lesions at Providence Saint John's Health System from July 2007 to November 2017. During this time, 21 patients underwent a fully endoscopic endonasal transpterygoid approach for Meckel's cave pathology. We specifically included only those patients with imaging-ambiguous pathologies located primarily in Meckel's cave to highlight the wide range of pathologic processes that can occur

Discussion

There are numerous pathologies that can affect Meckel's cave and the Gasserian ganglion. Trigeminal schwannomas and meningiomas are the most common, followed by epidermoid cysts, head and neck sarcomas, chordomas, and sinonasal malignancies. However, this area can also be the site of many rare pathologic lesions. Some inflammatory conditions (idiopathic inflammatory sensory neuropathy, Wegener's granulomatosis, or sarcoidosis), vascular pathologies (cavernous hemangioma, aneurysm), and more

Conclusions

For isolated lesions involving Meckel's cave, biopsy often is required to confirm the diagnosis and to determine the appropriate treatment strategy. The endoscopic endonasal transpterygoid approach provides direct and minimally invasive access to Meckel's cave and diseases extending along V2 and V3, such as head and neck carcinomas with perineural spread, without risking additional cranial nerves, intracranial contents, or other critical neurovascular structures. This approach is a safe

Acknowledgments

We thank the John Wayne Cancer Institute at Providence Saint John's Health Center in Santa Monica, California, for their ongoing support of our research.

References (21)

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Conflict of interest statement: Dr. Daniel Kelly receives royalties from Mizuho Inc. Dr. Garni Barkhoudarian is a consultant for Vascular Technologies Inc. The other authors have no relevant disclosures for this case report to declare.

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