# Crista Galli Pneumatization Complicating Olfactory Groove Meningioma Resection: A Case Report

## TL;DR

A rare case of a large pneumatized crista galli complicating the surgical removal of an olfactory groove meningioma is reported, highlighting the need for adjusted surgical approaches.

## Contribution

This case report highlights the clinical relevance of preoperative CT imaging to detect anatomic variants like pneumatized crista galli in meningioma surgery.

## Key findings

- A 22-year-old male with a 4cm olfactory groove meningioma had a large pneumatized crista galli identified preoperatively.
- A modified bilateral frontal craniotomy was used to achieve a Simpson 2 resection despite the anatomical challenge.
- Preoperative CT imaging is emphasized as essential to identify anatomic variations and adjust surgical strategies.

## Abstract

Pneumatization of the crista galli (PCG) is an anatomic variant of the osseous skull base. Olfactory groove meningiomas (OGMs) arise in the vicinity of the crista galli, and PCG may be an obstacle to complete resection from a preferred unilateral approach.

A 22-year-old male presented with symptoms of chronic frontal headaches and was found to harbor a 4cm OGM. Preoperative imaging workup also revealed the presence of a very large PCG with a height of 27mm above the floor of the anterior fossa.

Given the presence of PCG, we elected to adjust our conventional approach of a unilateral pterional/subfrontal craniotomy to a modified bilateral frontal craniotomy, which was a combination of a large right-sided pterional and a small left-sided frontolateral osteotomy, sparing the midline. This allowed excellent access to the floor of the anterior fossa, allowing us to achieve a favorable Simpson 2 resection. Apart from iatrogenic anosmia, the patient had an uneventful recovery.

The preoperative work-up of OGM patients should include dedicated CT imaging of the skull base to assess potential variations in the aeration status of the paranasal sinuses and ethmoidal cells. This is of great clinical relevance as it allows for the detection of variations such as a PCG. This can prompt an adjustment of the operative strategy to minimize the risk of postoperative cerebrospinal fluid (CSF) leak and meningitis.