Growth dynamics of Rathke's Cleft cyst: a risk score system for surgical decision making

Rathke's cleft cysts (RCCs) exhibit variable growth patterns, thus posing a challenge in predicting progression. While some RCCs may not cause symptoms, others can insidiously cause pituitary dysfunction, which is often irreversible, even following surgery. Hence, it is crucial to identify asymptomatic RCCs that grow rapidly and pose a higher risk of causing endocrinologic dysfunction. This enables timely surgical intervention to prevent permanent damage. Our study examines the growth rate of RCCs, identifies factors that accelerate growth, and discusses the clinical implications of these findings.

A retrospective analysis of a prospectively maintained electronic database revealed 45 patients aged 18-80 years who underwent endoscopic endonasal surgery (EEA) for RCCs between 2010 and 2022 at our center. Of these, 20 required early operative intervention. The remaining 25 patients were followed closely clinically and radiologically before requiring surgery (initial conservative management group). We conducted an analysis of the factors predicting growth over time in this group. Using a regression model, we constructed a risk score system to predict RCC growth over time.

Patients in the initial conservative group had smaller cysts and were generally older than those in the early surgery group. Patients with preoperative pituitary dysfunction showed a higher median growth of 1.0 mm in the longest diameter compared to those with normal pituitary function, with an increase of 0.5 mm. A sum of annual cyst growth of all (z, y, x) diameters, at a rate of 3 mm or greater, was associated with a clinically significant increase in the risk of pituitary dysfunction, exceeding 50%.The most significant factors predicting rapid growth in RCCs were smoking status, age, and T1-weighted magnetic resonance imaging (MRI) intensity of cysts. Smoking was the most critical risk factor for rapid cyst growth (p =  < .001). Our risk score system accurately predicted RCC growth with a 74% accuracy rate, 73% sensitivity, and 75% specificity.

Our analysis showed a strong link between active smoking and the rapid growth of RCC. This novel finding has significant preventive implications but needs validation by a large population database. Surgical intervention for RCC currently is often reserved for symptomatic cases. However, utilizing our risk-based scoring system to predict rapidly growing cysts may indicate early surgery in minimally symptomatic patients, thereby potentially preserving pituitary function.