# Clinicoradiological Dissociation in a Giant Lytic Posterior Fossa Epidermoid Cyst: A Case Report

## TL;DR

A 74-year-old woman with a large brain cyst showed mild symptoms despite severe imaging findings, highlighting unusual clinical and radiological differences.

## Contribution

This case report presents a rare instance of clinicoradiological dissociation in a giant posterior fossa epidermoid cyst.

## Key findings

- The patient had a giant epidermoid cyst with bone lysis but no acute neurological issues.
- MRI and CT scans showed severe findings, but the patient had only mild symptoms.
- Surgical resection confirmed the diagnosis and resolved the condition.

## Abstract

Intracranial epidermoid cysts (ECs) are rare benign congenital lesions characterized by slow growth and late clinical presentation. Giant ECs of the posterior fossa are exceptionally uncommon and typically associated with early neurological deterioration due to the confined anatomy in this region. We report the case of a 74-year-old woman presenting with chronic headache and mild vertigo, with no focal motor or cranial nerve deficits. MRI revealed a giant extra-axial EC of the left posterior fossa with occipital bone lysis on CT scan. Despite the radiological findings, no acute hydrocephalus or intracranial hypertension was present. The patient underwent surgical resection. Histopathological examination confirmed the diagnosis of an EC. This case highlights the striking clinicoradiological dissociation that may be observed in giant posterior fossa ECs.