# Extremely Rare Presentation of Pilonidal Sinus Disease in the Posterior Cranial Fossa of a 2-Year-Old Patient: A Case Report

## TL;DR

A 2-year-old child had a rare case of pilonidal sinus disease in the brain, diagnosed after a seizure and surgery.

## Contribution

This case report highlights an extremely rare presentation of pilonidal sinus disease in the posterior cranial fossa of a young child.

## Key findings

- The patient exhibited a generalized tonic-clonic seizure followed by fever and loss of consciousness.
- MRI revealed a cystic lesion in the posterior fossa, leading to surgical resection and histopathological confirmation of pilonidal sinus disease.
- The patient recovered well post-surgery and was discharged in good health.

## Abstract

A 2-year-old female patient presented after experiencing a generalized tonic-clonic seizure accompanied by fever, followed by a loss of consciousness. She underwent an urgent right frontal external ventricular drain placement. Intraoperative cerebrospinal fluid analysis was negative for infectious patterns. MRI showed a predominantly cystic lesion in the midline posterior fossa, with a compressive mass effect. Subsequently, she underwent a suboccipital craniotomy for microscopic resection of a posterior cranial fossa lesion. Histopathology reported keratin flakes with severe active inflammation, and foreign body type giant cell reaction in scalp excision with free hair shafts through the inflammatory focus, consistent with pilonidal sinus. The patient was then discharged home in good health.