A 57 year-old gentleman with uncomplicated Type 2 Diabetes Mellitus and 30 pack year smoking history was assessed in outpatient endocrinology clinic with a 4 month history of non-specific symptoms, including dizziness, lack of energy and intermittent bi-frontal headaches described as pressure behind the eyes. There was no history of exogenous steroid use. Bloods at 0833 h identified deficiency in testosterone (<1 nmol/l; N= 630 nmol/l), thyroxine (free T4 6.8 pmol/l; N=919 pmol/l) and cortisol (<27 nmol/l). Prolactin was raised (884 nmol/l; N=73407 mU/l). To our surprise, MRI Pituitary with contrast reported empty sella syndrome due to appearances of chronic expansion of the sella, cerebrospinal fluid (CSF) within this space and a thin looking pituitary gland. The patient was managed conservatively with hormone replacement. Following Pituitary Multidisciplinary Team evaluation, a revised diagnosis of intrasellar cyst was made due to a thin cystic wall apparent following careful inspection of the MR images. The patient awaits surgical assessment for definitive management. Cystic lesions within the sellar region are classified by site of origin (sella, suprasellar or infrasellar), tissue of origin, and histological appearances (commonly Rathkes cleft cysts or arachnoid cysts). Sellar cystic fluid signal intensity on T1WI and T2WI are equal to CSF, non-enhancing and diffusion negative and therefore present diagnostic challenges, particularly when this cyst is confined to the sellar. Varying degrees of pituitary dysfunction have been reported with sellar cysts. We echo the concerns made by Topliss and colleagues in 1977, recommending caution when evaluating an empty sella on neuroimaging. MRI is considered gold standard and experts recommend using a dedicated sella protocol which minimises the risk of missing sellar cysts. CT cisternography has been suggested as a useful adjunct to overcome this rare but important issue. With advancing neuroimaging technologies we hope future cases dont re-appear in the literature in another 4 decades time.
11 Nov 2019 - 13 Nov 2019