A case of left homonymous upper quadrantanopia after inferior petrosal sinus sampling to investigate acromegaly with empty sella

Abstract

Diagnosing and treating acromegaly are difficult when imaging of the pituitary gland fails to show an adenoma. Inferior petrosal sinus sampling (IPSS) is a useful diagnostic technique that can aid in both the localization of tumors and lateralization within the pituitary gland. However, some severe neurological complications have been reported in the literature, including brain stem injuries, thromboembolism, isolated sixth nerve palsy, and venous subarachnoid hemorrhage. Here, we report a rare complication of left homonymous upper quadrantanopia after inferior petrosal sinus sampling. A 58-year-old woman with a 10-year history of hypertension was referred to our endocrine clinic for evaluation of acromegaly. She presented with macroglossia, prognathism, and acral enlargement of both hands. Her visual field test was normal. An elevated insulin-like growth factor-1 (IGF-1) level of 902 ng/mL and a nadir growth hormone (GH) level of 8.7 ng/mL on the oral glucose tolerance test confirmed the diagnosis of acromegaly. Magnetic resonance imaging (MRI) revealed an empty sella but no evidence of a pituitary adenoma (Fig. 1A). An In-octreotide scan did not show evidence of ectopic or GH-secreting tumor, so we decided to use IPSS to determine the source of pituitary GH