Endocrine Abstracts

Rathke’s cleft cysts (RCC) arise from the embryonic remnants of Rathke’s pouch in the anterior pituitary gland. The majority are asymptomatic and incidentally diagnosed when the pituitary is imaged for other reasons. RCCs can progress to requiring surgical intervention for hormonal and structural effects. It is unclear what factors determine RCC enlargement and over what period this occurs, hence need for long term follow-up is uncertain. We analysed our conservatively managed RCCs to determine rates of growth.

Methods: Radiology reports were searched for term ‘Rathke’. Patients with conservatively managed RCC, and at least two interval pituitary MRIs were selected. Scans were double reported by two neuroradiologists and cyst dimensions recorded: Anterorposterior-AP; Craniocauda-CC; Lateral-Lat. Comparison was made between the most recent and first scan: increase/decrease in size defined as ≥/≤3mm. Clinical data was retrieved from medical records.

Results: Seventy-four patients (mean follow up 41 months) were identified after excluding those having intervention, co-existing pituitary adenoma and uncertain diagnosis. RCC was diagnosed incidentally in 58% (43/74), through headache investigation in 32% (24/74) and hypogonadotrophic hypogonadism investigation in 8% (6/74). 7% (5/74) had TSH deficiency, 3%(2/74) had ACTH deficiency,3%(2/74) GH deficiency and 5% gonadotrophin deficiency (4/74). In terms of growth, we found that 9.5% (7/74) increased in size (average 4mm at median follow-up 71 months); 18.9% (14/74) decreased in size (average 5mm at median follow-up 34 months); 71.6% (53/74) are stable (median follow up 36 months). Two patients progressed to requiring intervention during this period. There was no predilection for increase in a single cyst dimension.

Conclusion: Conservatively managed RCCs may increase in size and interval imaging is required for monitoring. However, given only 2 patients progressed to requiring intervention and 18.9% actually decreased in size, the health economics and rationale for long term imaging require evaluation.