Acromegaly with empty sella syndrome

Reyna Daya; Faheem Seedat; Khushica Purbhoo; Saajidah Bulbulia; Zaheer Bayat

doi:10.1530/EDM-21-0049

Acromegaly with empty sella syndrome

Endocrinol Diabetes Metab Case Rep. 2021 Jul 1:2021:21-0049. doi: 10.1530/EDM-21-0049. Online ahead of print.

Authors

Reyna Daya^{1

2}, Faheem Seedat^{1

2}, Khushica Purbhoo³, Saajidah Bulbulia^{1

2}, Zaheer Bayat^{1

2}

Affiliations

¹ Division of Endocrinology and Metabolism, Department of Internal Medicine, Helen Joseph Hospital, Rossmore, Johannesburg, South Africa.
² Division of Endocrinology and Metabolism, Department of Internal Medicine, Faculty of Health Sciences, School of Clinical Medicine, University of the Witwatersrand, Johannesburg, South Africa.
³ Department of Nuclear Medicine and Molecular Imaging, Chris Hani Baragwanath Academic Hospital and Charlotte Maxeke Johannesburg Academic Hospital, Faculty of Health Sciences, University of Witwatersrand, Johannesburg, South Africa.

Abstract

Summary: Acromegaly is a rare, chronic progressive disorder with characteristic clinical features caused by persistent hypersecretion of growth hormone (GH), mostly from a pituitary adenoma (95%). Occasionally, ectopic production of GH or growth hormone-releasing hormone (GHRH) with resultant GH hypersecretion may lead to acromegaly. Sometimes localizing the source of GH hypersecretion may prove difficult. Rarely, acromegaly has been found in patients with an empty sella (ES) secondary to prior pituitary radiation and/or surgery. However, acromegaly in patients with primary empty sella (PES) is exceeding rarely and has only been described in a few cases. We describe a 47-year-old male who presented with overt features of acromegaly (macroglossia, prognathism, increased hand and feet size). Biochemically, both the serum GH (21.6 μg/L) and insulin-like growth factor 1 (635 μg/L) were elevated. In addition, there was a paradoxical elevation of GH following a 75 g oral glucose load. Pituitary MRI demonstrated an ES. In order to exclude an ectopic source of GH hypersecretion, further biochemical tests and imaging were done, which were unremarkable. Notably, increased uptake in the sella turcica on the 68Gallium DOTATATE PET/CT confirmed the ES as the likely source of GH secretion. As no overt lesion was noted, medical treatment (octreotide acetate) was initiated with a good clinical and biochemical response. At his 3 month follow-up, he reported an improvement in symptoms (fatigue and headache), however he still complained of low libido. Due to a persistently low testosterone level at follow-up, a long-acting testosterone was initiated. His GH level normalised, and IGF-1 has significantly reduced.

Learning points: The commonest cause of acromegaly is due to GH hypersecretion from pituitary adenomas (95%). Acromegaly has rarely been found in patients with ES. It is important to exclude a past history suggestive of pituitary apoplexy. Extra-pituitary source of GH such as ectopic production of GHRH with resultant GH hypersecretion needs to be excluded. In such cases, since there is no resectable mass, medical therapy is the primary treatment option.