Introduction: 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.
Evidence acquisition: 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.
Evidence synthesis: Fifty-one patients (23 reports, plus our cases) were analyzed from the literature. 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.