Changing characteristics of a colloid cyst of the third ventricle

Spontaneous Change in Density of Colloid Cyst: An Unusual Phenomenon

BACKGROUND

Colloid cysts of the third ventricle are benign congenital lesions. They are at times totally asymptomatic or may be detected in the evaluation for headache, neurologic disturbances, or psychiatric disturbances. They may sometimes cause grave consequences such as coma or even sudden death. The radiologic appearance is unique and important for making decisions in the management.

CASE DESCRIPTION

We report a patient with a colloid cyst who presented to us after sudden deterioration in consciouness. It was noted that he underwent brain computed tomography (CT) scan 10 months ago in the evaluation of headache. Compared with previous CT scan, there was a sudden change in the density and size of the colloid cyst with obstructive hydrocephalus. This unique change in the character of the colloid cyst occurred without any intervention. We discuss the possible etiologies behind this phenomenon along with a review of the literature.

CONCLUSIONS

This case stands out remarkably because it is only the second case in literature with similar natural history.

Spontaneous resolution of colloid cyst of the third ventricle: Implications for management

While there is little controversy regarding the treatment of symptomatic colloid cysts, the optimal management of “incidentally” detected and asymptomatic colloid cyst remains unclear. The age of the patient, duration and significance of symptoms related to the cyst, size and radiological characteristics of the cyst and the presence of hydrocephalus are all factors to be considered before considering surgery. While surgery most often provides good results in the majority of patients, complications do occur. Despite growing literature about the natural history of this condition, to date, only three cases of spontaneous resolution of colloid cyst <10 mm have been reported. We report the case of spontaneous resolution of a colloid cyst larger than 10 mm, initially managed with close observation and serial neuroimaging. This case highlights the possible role for a conservative approach even in larger-sized cysts.

Extruded contents of colloid cysts after endoscopic removal

OBJECTIVE

Mineralized or desiccated colloid cysts pose some unique challenges to endoscopic removal. The extrusion of the solid matrix into the intraventricular compartment has not been previously reported and, as such, no guidance exists regarding its predilection, prevention, and fate.

METHODS

Postoperative imaging studies in a registry of patients undergoing endoscopic removal of colloid cyst were reviewed to detect any solid matrix within the ventricular compartment. Preoperative images and operative notes were used to determine if any features were predictive. Serial postoperative images and clinical notes were used to characterize the implications of these findings.

RESULTS

From a review of 94 patients, 10 (10.6%) patients had evidence of an extruded intraventricular solid fragment (median follow-up 4 months; range 0.5–115 months). Of the evaluable patients, 7 of 9 patients had T1-weighted hyperintense and T2-weighted hypointense cysts on preoperative scans. Seventy-eight percent of the extrusions were on the same side as the endoscopic entry. Three patients demonstrated early fragment migration, but not after 8 months of radiological follow-up. All evaluable patients demonstrated improvement in their hydrocephalus, and none suffered a complication attributable to the intraventricular extruded fragments.

CONCLUSIONS

Intraventricular extruded colloid fragments can occur after endoscopic resection, with the possible risk demonstrated as cyst hypointensity on preoperative T2-weighted images. The finding does not seem to result in any clinical morbidity, and radiographic involution is the rule. Migratory capacity, however, does exist and justifies a more frequent imaging surveillance schedule and consideration for removal.

Interhemispheric transcallosal transforaminal approach and its variants to colloid cyst of third ventricle: Technical issues based on a single institutional experience of 297 cases

Context:

Colloid cysts are benign intracranial lesions that usually involve the anterior third ventricle with varying appearance on imaging studies. The number of articles debating the origin of this tumor is surpassed by papers proposing the best modality available for its treatment

Aim:

The purpose of this study is to analyze the clinical presentation and surgical outcome of colloid cysts surgically managed over a period of thirty-two years and evaluate the technical issues based on our experience.

Study Design:

This is a retrospective case series study.

Materials and Methods:

This is a retrospective case series study on 297 consecutive patients with colloid cysts who were operated. The case records of all the patients were evaluated to record the clinical symptoms and signs, imaging findings, surgical procedure, complications and follow-up data.

Results:

There were 178 (60%) males and 119 (40%) females, their age ranging from 9 to 66 years with a mean age of 28 years. The mean duration of symptoms was 1.8 months. Raised intracranial pressure headache was the most common initial presenting symptom followed by visual blurring, memory disturbance and drop attacks with gait unsteadiness. The tumor was an incidental imaging finding in five patients (2%). While an interhemispheric transcallosal approach was used in 275 (92.6%) patients, it was trans-cortical in 22 (7.4%). Twenty-two patients required emergency surgery in view of worsening sensorium. Postoperative complications included memory impairment, limb weakness and seizures. Despite documented complete excision of the tumor in 6 cases, 8 patients had recurrence of tumor during follow-up.

Conclusion:

Colloid cysts are potential life threatening but benign lesions that can be removed safely with low morbidity and mortality through the interhemispheric transcallosal approach and its variants. The possibility for recurrence warrants, close imaging follow-up after surgery. It is essential for neurosurgeons to be familiar with the different transcallosal approaches to reach the third ventricle especially for a posteriorly situated cyst and a narrow foramen of Munro.

Xanthogranulomatous colloid cyst of the third ventricle

Colloid cyst in the third ventricle is a common entity, whereas a variant of it, namely xanthogranulomatous, is quite rare. The closest imaging differential diagnosis is a purely third ventricular craniopharyngioma. We herein describe a case of xanthogranulomatous colloid cyst presenting with hydrocephalus.

Pediatric colloid cysts of the third ventricle: management considerations

PURPOSE

Pediatric colloid cysts (CC) have a congenital origin, and yet, there are very few studies focussing exclusively on their occurrence in the pediatric population. Pediatric CC has been associated with more aggressive clinical and radiological patterns than their adult counterparts. In this study, undertaken on children with anterior third ventricular CC, excised using the interhemispheric transcallosal approach, the characteristic clinicoradiological features and management options are studied.

METHODS

Five pediatric patients (aged 16 years or less; mean age 13.8 years; mean duration of symptoms:7.6 months) out of 38 patients with CC operated between 1995 to 2009 were included. The clinical manifestations included those of raised intracranial pressure (n = 4); exacerbation of occipital headache on reading (n = 1); secondary optic atrophy (n = 3); and, drop attacks (n = 1). On computed tomography scan, the cyst was hyperdense, enhancing in two patients and not enhancing in three patients. All had bilateral lateral ventricular dilatation with periventricular lucency. On magnetic resonance imaging (n = 3), the cyst was T1 hypointense and T2 isointense in one, hyperintense on both T1 and T2 with a hypointense capsule and nonenhancing on contrast in one (with a giant colloid cyst), and T1 hyperintense and T2 hypointense in one patient. An interhemispheric, transcallosal trajectory combined with transforminal approach (n = 3); combined transforminal and subchoroidal approaches (n = 1); and, interforniceal approach (n = 1) were used.

RESULTS

Total excision was performed in four patients. In one patient, a small part of capsule was left attached to thalamostriate vein. Symptoms of raised intracranial pressure showed improvement in all the patients with resolution of hydrocephalus. There was no tumor recurrence at follow-up.

CONCLUSIONS

Pediatric colloid cysts are rarer than their adult counterparts due to their late detection only after manifestations of raised intracranial pressure, visual or cognitive dysfunction or drop attacks occur. Their radiological appearance varies depending upon the amount of mucoid content, cholesterol, proteins, and water content. The fast development of clinical manifestations in children may be related to rapid enlargement of cyst due to higher water content within them. The transcallosal approach is the "gold standard" of surgery and usually ensures gratifying and lasting results.

Unique MR spectroscopic finding in colloid-like cyst

Cysts morphologically identical to colloid cysts are rarely reported to be located in areas outside the third ventricle. We report the magnetic resonance (MR) imaging and spectroscopic findings in three patients with colloid like cyst located in the ponto-medullary, pre-pontine cistern and suprasellar region. The MR imaging and spectroscopy performed on a 1.5-tesla scanner in three female patients revealed T1 hyperintense mass lesions. A large dominant metabolite peak at 2.0-ppm chemical shift, simulating N-acetylaspartate (NAA) of normal neuronal tissue was detected within the lesion. This peak is probably due to the presence of glycoproteins secreted by the ciliated columnar epithelium lining these cysts. MR spectroscopy of colloid cyst has not been described in the literature and hence the findings in this study will help in the diagnosis of this cystic lesion especially when located at unusual location. The signal characteristics of these cysts in various sequences including diffusion weighted imaging (DWI) and susceptibility weighted imaging (SWI) are also discussed.

Change in CT radiodensity of a colloid cyst of the third ventricle: case report and literature review

A unique case is presented of a decrease in density on CT scans of a colloid cyst of the third ventricle with time. This occurred in the absence of any operative intervention in a 35-year-old woman.

Spontaneous rupture of a presumed colloid cyst of the third ventricle--case report

An 83-year-old man presented with gait disturbance, dementia, and urinary incontinence that had progressed over 2 months. Computed tomography (CT) of the brain revealed hydrocephalus due to a well-demarcated, round hyperdense mass in the third ventricle, which was not enhanced by contrast agent. Ten days after the initial evaluation, CT revealed that the cyst in the third ventricle had disappeared. Magnetic resonance imaging revealed spontaneous rupture of the lesion and remnants of cyst wall anchored to the anterior roof of the third ventricle. Thereafter, the symptoms of hydrocephalus subsided. However, 6 months later the patient's condition gradually deteriorated and the ventricles dilated without any evidence of tumor regrowth. Surgical intervention was not performed as the family of the patient withheld consent. The natural history of colloid cysts of the third ventricle remains unclear. Spontaneous rupture of a presumed colloid cyst of the third ventricle should be considered when planning treatment.