A 16-year old man with an intradural extramedullary arachnoid cyst in the spine: a rare case

Intradural extramedullary arachnoid cyst in the spine is an extremely uncommon cyst, only 5% occurs in the spine. This cyst rarely causes compression to the spinal cord. The etiology of this cyst is not known for certain, but the majority of which is congenital with other possible causes such as trauma, infection, inflammation, postoperative complication, and lumbar puncture. Arachnoid cyst is categorized into three types according to Nabor et al, which is type I (IA and IB), type II, and Type III. Diagnosis establishment was carried out through imaging modality of MRI with contrast. If the case is asymptomatic, observation as a conservative therapy is advised. Total cyst excision is recommended for patients with clinical symptoms and severe neurological damage. In this article, we report a case of a 16-year-old male patient who came with the main complaint of neck pain that radiated to the upper back, down to his arms and both of his hands for the past 4 months before hospital administration. This was followed by weaknesses in all of his extremities and difficulties when urinating and defecating. Based on MRI, C3-C5 intradural extramedullary arachnoid cyst was detected and the patient had undergone total cyst excision surgery with a promising result that shows the increased value for the four limbs and decreased pain. An intradural extramedullary arachnoid cyst is an extremely rare cyst. This case utilized MRI with contrast as the imaging modality, proving to be very helpful in establishing diagnosis.