Giant, calcified colloid cyst of the lateral ventricle

Giant colloid cyst occupying a cavum septum pellucidum et vergae

Colloid cysts are uncommon, intracranial lesions frequently arising from the anterior aspect of the third ventricle. Rarely a cyst presents greater than 30 mm diameter as a giant colloid cyst. This case reports a patient with a giant colloid cyst occupying a cavum septum pellucidum et vergae. The clinical and operative significance of this anatomical variation is discussed and the giant colloid cyst literature reviewed.

Imaging of spontaneous intraventricular rupture of a septum pellucidum colloid cyst: case report

Intraventricular rupture of a colloid cyst is a rare phenomenon and has been proposed as a mechanism for sudden death in patients with colloid cysts. Imaging of a colloid cyst during rupture has been described in only one other instance. The authors report a highly unusual case of a 53-year-old man who presented with acute onset headaches and imaging findings of hydrocephalus caused by a colloid cyst originating from the septum pellucidum and superior surface of the roof of the third ventricle. Interestingly, the colloid cyst revealed imaging signs of intraventricular rupture characterized by a tail-like drainage of cystic contents into the occipital horn of the lateral ventricle. The patient was surgically treated with a craniotomy and transcallosal approach to the colloid cyst, where it was noted that the cyst wall was spontaneously open. This rare case highlights unique imaging findings of a rare event in an infrequent pathology confirmed with intraoperative microscopy. The authors further document the process of cyst rupture and speculate on its pathomechanisms.