A retrospective review of the clinical, biochemical and radiological spectrum of adrenal incidentalomas at Tygerberg Academic Hospital, South Africa.
TL;DR
It was demonstrated that PCC and cortisol-producing adenomas were the most common functional tumours in patients diagnosed with AI at Tygerberg Hospital, in contrast to most international studies, which show MACS as the most common functional AI.
Abstract
Background
An adrenal incidentaloma (AI) is a clinically unapparent adrenal mass >1 cm detected during imaging performed for reasons other than adrenal disease. The approach to AI is discussed extensively in international literature, but not specifically in resource-limited settings such as South Africa (SA).
Objective
To describe the clinical, biochemical and radiological spectrum of AIs at Tygerberg Hospital (TBH), Cape Town, SA.
Methods
This study was a retrospective descriptive review of all patients diagnosed with AI at TBH during the study period (1 January 2009 - 31 December 2023).
Results
Two hundred and ninety-five (295) patient records were screened for inclusion using the radiology and admission records. Those excluded were duplicate entries (n=50), patients not meeting criteria for AI (n=47) and diagnosis of AI with no further investigation (n=113), leaving 85 patients included. A computed tomography scan was the most frequently utilised imaging modality (n=54; 64%). Indications were abdominal pain (n=27; 32%), other gastrointestinal complaints (n=10; 12%), abdominal mass (n=7; 8%), trauma (n=3; 4%) or other (n=38; 45%). Non-functional tumours comprised 87% (n=74). Functional tumours included pheochromocytoma (PCC) (n=5; 45%), mild autonomous cortisol secretion (MACS) (n=3; 27%), primary hypercortisolaemia (n=2; 18%) and androgen-producing tumours (n=1; 9%). Fourteen patients (16%) had surgery.
Conclusion
Our study demonstrated that PCC and cortisol-producing adenomas were the most common functional tumours. This is in contrast to most international studies, which show MACS as the most common functional AI. This likely reflects regional screening bias and underutilisation of dexamethasone suppression testing, rather than the true disease prevalence of PCC in the Western Cape Province. A large proportion of patients with a diagnosis of AI did not undergo any further investigation. Awareness among clinicians and collaboration with radiologists for early identification and referral of AI cases is imperative.