Huge familial colloid cyst of the third ventricle: An extraordinary presentation

Endoscopic trans-septal interforniceal approach for excision of colloid cysts of the third ventricle using the rotational technique

Colloid cysts of the third ventricle are benign intracranial lesions that account for 0.5 to 2% of all brain tumors and are even rarer in pediatric population. Dandy was the first to successfully excise a colloid cyst of the third ventricle via a transcortical transventricular approach in 1921. For several decades to follow, the transcortical transventricular and transcallosal microsurgical approaches remained the cornerstone of surgical management of these lesions. With time and refinements in endoscopic equipment and techniques, endoscopic resection of colloid cysts evolved into a currently well-established and appealing minimally invasive alternative to microsurgery. Endoscopic endochannel techniques for colloid cysts of the third ventricle may either be transforaminal or trans-septal interforniceal, depending on the pathoanatomical features of the colloid cyst and its relation to the juxtaposed anatomical structures. The endoscopic trans-septal interforniceal approach is required to access the rare subset of colloid cysts that extend superior to the roof of the third ventricle between the two fornices insinuating themselves between the leaflets of the septum pellucidum. In this article, the surgical technique of the endochannel endoscopic trans-septal interforniceal approach is elaborated upon. A representative case is presented along with an operative video.

Familial colloid cysts: not a chance occurrence

PURPOSE

Colloid cysts are rare, benign brain tumors of the third ventricle with an estimated population prevalence of 1 in 5800. Sudden deterioration and death secondary to obstructive hydrocephalus are well-described presentations in patients with a colloid cyst. Although historically conceptualized as driven by sporadic genetic events, a growing body of literature supports the possibility of an inherited predisposition.

METHODS

A prospective registry of patients with colloid cysts was maintained between 1996 and 2021. Data pertaining to a family history of colloid cyst was collected retrospectively; self-reporting was validated in each case by medical record or imaging review. Frequency of patients with a documented first-degree family member with a colloid cyst based on self-reporting was calculated. The rate of familial co-occurrence within our series was then compared to a systematic literature review and aggregation of familial case studies, as well as population-based prevalence rates of sporadic colloid cysts.

RESULTS

Thirteen cases with affected first-degree relatives were identified in our series. Of the entire cohort, 19/26 were symptomatic from the lesion (73%), 12/26 (46.2%) underwent resection, and 2/26 (7.7%) had sudden death from presumed obstructive hydrocephalus. The majority of transmission patterns were between mother and child (9/13). Compared with the estimated prevalence of colloid cysts, our FCC rate of 13 cases in 383 (3.4%) estimates a greater-than-chance rate of co-occurrence.

CONCLUSION

Systematic screening for FCCs may facilitate early recognition and treatment of indolent cysts, thereby preventing the rapid deterioration that can occur with an unrecognized third ventricular tumor. Furthermore, identifying a transmission pattern may yield more insight into the molecular and genetic underpinnings of colloid cysts.

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.

Genetics of Colloid Cyst in Monozygotic Twins: Case Report and Review of Literature

BACKGROUND

Colloid cysts are rare developmental lesions, accounting for approximately 1% of intracranial tumors. Often, these benign lesions are asymptomatic, but they are associated with significant mortality as a result of acute hydrocephalus. This mortality in patients with vague or no symptoms dictates a need for better understanding of the etiology of colloid cysts to expedite diagnosis and management. We present a case of monozygotic twins with colloid cysts to propose a genetic etiology for colloid cyst.

CASE DESCRIPTION

Previously healthy male monozygotic twins presented 4 years apart with headache secondary to hydrocephalus as a result of colloid cysts. Both patients underwent multiple surgeries and were doing well at last follow-up.

CONCLUSIONS

The present case adds to a body of literature of familial colloid cysts, suggesting higher concordance in monozygotic compared with dizygotic twins. This may be due to high genetic load, shared intrauterine environment, epigenetic changes, or genetic mutation. This literature review suggests that given high morbidity and mortality of colloid cysts, screening may be beneficial. Even in the absence of a single, definitive genetic etiology, we recommend consideration of genetic screening or, at a minimum, screening with neuroimaging for monozygotic twins in cases where 1 twin is diagnosed with colloid cyst.

Familial Colloid Cysts of the Third Ventricle: Case Report and Literature Review

Colloid cysts of the third ventricle are rare lesions. To our knowledge, only 23 familial cases of colloid cysts have been reported in the literature. The country of origin of the patients with familial cases had not been previously studied as a group. A 49-year-old female patient from Puerto Rico and her 21-year-old daughter underwent surgical resection for colloid cysts within a period of 5 years. The daughter presented with symptomatic hydrocephalus, while the mother only had mild chronic headaches. The occurrence of a colloid cyst in this family prompted us to perform a literature review and tabulate all the familial cases. This report presents the 24^th case of a familial colloid cyst, and the fourth involving a mother and daughter. Australia is the country with the largest amount of reported cases. For smaller countries such as Sweden and Finland, two cases had been reported for each of them. Due to the unlikely probability of familial colloid cyst occurring at random, a genetic component is likely to be involved. The occurrence of several reports from patients from Australia, Finland, Sweden, and Puerto Rico where the population is smaller or more segregated may also suggest a genetic inheritance. Screening of first-degree-related subjects is recommended for families in which two or more members are affected. The presence of a colloid cyst in a twin mandates neuroimaging in the other twin, as there are five familial cases in twins reported in the literature.

Are familial colloid cysts of the third ventricle associated with a worse clinical course than sporadic forms? Case illustration and systematic literature review

BACKGROUND

The incidence of asymptomatic colloid cysts is increasing due to the widespread use of neuroimaging tools. According to previous works, familial forms (within first-degree relatives) represent 5-25% of the cases, and it is not clear whether they display specific features influencing the clinical behavior of the disease.

METHODS

We reviewed the literature to extract data from papers dealing with familial colloid cysts. For comparison, previous series dealing with the natural history of sporadic cases were identified. Also, we present two more cases of familiar colloid cysts from our experience.

RESULTS

Fifty-one patients (23 reports, plus our cases) were analyzed. Familial cases showed a younger age at diagnosis (p=0.02) and fewer asymptomatic cases (p<0.001) compared to non- familial colloid cysts. The odds ratio and relative risk of needing surgery with a positive family history for surgical cyst removal were respectively 17.5 (CI: 1.6 - 197.4) and 1.9 (CI: 0.71 - 5.1). Screening of other family members identified further colloid cysts in 4% of families.

CONCLUSIONS

Familial colloid cysts show a higher percentage of younger and symptomatic patients compared to non-familiar forms. A positive family history for surgical evacuation is a predictor for a similar outcome. This could indicate a predisposition to an earlier formation and faster growth, and the need for a stricter follow-up in asymptomatic patients. If confirmed in the future, this could suggest a review of the criteria for cyst treatment and extend the surgical indication to asymptomatic familial cases.