Natural course of Rathke’s cleft cysts and risk factors for progression

OBJECTIVE Rathke’s cleft cysts (RCCs) are relatively common and often detected incidentally. They are usually asymptomatic and managed conservatively. However, little is known about their natural history. Thus, the authors aimed to examine the natural course of RCCs and identify the risk factors for their progression. METHODS This retrospective study examined 229 patients (median age 43.0 years) diagnosed with RCCs by MRI and followed up without surgery (median period 36.6 months). The median cyst height on the initial MRI was 10 mm. Progression or regression of RCC was defined as cyst height changes of ≥ 1 mm. RESULTS In total, 23 (10.0%) RCCs progressed, whereas 73 (31.9%) RCCs spontaneously regressed. The remaining 133 were noted to be stable throughout the follow-up period. Patients with progressed RCCs were significantly older than those with stable RCCs. In patients with acute headache as an initial symptom, RCCs were significantly more likely to spontaneously regress. New symptoms occurred in 6 patients, 5 of whom underwent surgery for RCC progression. Of these 6 patients, 1 patient had persistent adrenocorticotropic hormone deficiency and 1 patient developed diabetes insipidus. Kaplan-Meier analysis results showed RCC progression and new symptom development rates to be 12.0% and 4.1% at 5 years and 13.7% and 5.7% at 10 years, respectively. CONCLUSIONS RCCs rarely progress or cause new symptoms in the long term. Patients with asymptomatic RCC should be followed up for at least 5 years to ensure RCC inactivity. RCCs in older adults may require greater surveillance.