“Atypical Radiological Findings In Colloid Cyst Of Third Ventricle- Rare Findings In Rare Tumour”

Abstract

Abstract Introduction-Colloid cysts are rare intracranial tumours occurring in 3 individuals per million per year. They constitute around 2% (range 0.5 to 3%)3-5 of all primary brain tumours. Materials and methods- We retrospectively studied the imaging of 47 patients of colloid cyst of third ventricle who were admitted in PGIMER, Chandigarh in last 10 years for surgical excision. Of them 31 underwent endoscopic excision while 16 went microsurgical excision. Preoperative NCCT head and MR imaging of all patients were studied. Results-Analysis revealed that in 91.5% cases cyst size was between 1 to 3 cm with mean cyst diameter of 17.55±8.32mm. We encountered 3 giant cysts (>3 cm) in our study. On NCCT head, cyst was hyperdense in 85.11% of cases, hypodense in 4.25% of cases and isodense in 10.64%. On T1 weighted MRI sequences, 42.55% of cysts were hyperintense, 31.92% were hypointense, while 25.53% were isointense. On T2 weighted sequences 57.45% of cysts were hyperintense, 38.30% were hypointense while 4.25% were isointense. Peripheral contrast enhancement was present in 8.51% of cysts. Two cysts showed intracystic haemorrhage, out of which one was giant cyst and one showed intramural nodule. Conclusion-This article describes case studies of patients with atypical findings in imaging like giant colloid cysts, peripheral contrast enhancement, intracystic haemorrhage & intramural nodule.