Suprasellar arachnoid cysts in adults: clinical presentations, radiological features, and treatment outcomes

A tendency for suprasellar arachnoid cysts (SACs) to occur in young children is known. Data of adult SACs were rare in previous reports. The aim of this study is to discuss their clinical presentations, radiological features, and treatment outcomes based on 23 adult patients who underwent endoscopic fenestration in our hospital between January 2003 and December 2018. Preoperative cyst volume ranged from 12.3 to 72.5 cm³ (mean 39.8 ± 19.8). Endocrine disorders occurred in 7 (30.4%) patients. Hydrocephalus was observed in 20 patients. In the patients with hydrocephalus, the mean preoperative Evans' index (EI) (%) and frontooccipital horn ratio (FOHR) (%) were 44.8 (ranged 32.2-63.4) and 49.6 (ranged 36.7-59.8), respectively. A bivariate correlation showed significant positive association between preoperative cyst volume and preoperative EI or FOHR (Pearson correlation, r = 0.607, p = 0.005; r = 0.583, p = 0.007). The slit-valve phenomenon was observed in 13 (56.5%) patients. Pale/tenacious cyst walls were observed in 12 (52.2%) patients. Postoperatively, all patients achieved the improvement in clinical symptoms and a decrease in cyst size. The mean decreases in cyst volume, EI, and FOHR were 64.7%, 7.89%, and 5.8%, respectively. A bivariate correlation indicated the irrelevance between the postoperative cyst volume and postoperative EI or FOHR (Pearson correlation: r = 0.37, p = 0.11; r = 0.43, p = 0.054). These results reveal that there are a few differences in several aspects between adult patients and child patients. The severity of hydrocephalus is correlated with cyst size in adult patients. Additionally, the excellent outcomes in adult SACs can be obtained by endoscopic fenestration.