Background
Adrenocortical carcinomas (ACC) typically follow an aggressive clinical course. The incidence of ACC is 1-2/million/year with a minority of ACC potentially linked to Multiple Endocrine Neoplasia type 1 (MEN 1). The prevalence of benign adrenocortical tumours in MEN 1 ranges between 20-73%, mostly adenomas or hyperplasia. The prevalence of ACC is believed to be 1-4% in MEN 1.
Aim
To examine the prevalence and behaviour of ACC and adrenal lesions in a large Tasmanian cohort with MEN 1.
Methods
A retrospective analysis of 95 MEN 1 patients in Tasmania with a common MEN 1 gene mutation was performed. All patients underwent one or more of ultrasonography, computed tomography (CT) and magnetic resonance imaging (MRI); 63 had CT, 29 had ultrasound and three had MRI. Fluorodeoxyglucose positron emission tomography (FDG PET) was also performed in 68/95 patients.
Results
Of 95 patients, forty-three (27 females and 16 males) (45.3%) had adrenal lesions. The median age of diagnosis of adrenal lesion was 48 years. All adrenal lesions were asymptomatic and found incidentally on imaging. Adrenal lesion size ranged between 9-51mm (median 15mm) with Hounsfield units ranged between -21 to 40 (median 10HU). Of 26 patients with CT results, 19 (73.1%) exhibited benign features (14 adenomas, two hyperplasia and three bulky adrenals). The remaining seven lesions were not further characterised. Of patients with FDG PET imaging, six showed FDG-avid lesions (one ACC, two metastatic neuroendocrine tumours, one benign adenoma and two with mild FDG-uptake of unclear clinical significance).
Conclusion
Adrenal lesions are common in MEN 1, however ACC is rare. Routine abdominal imaging is useful in detecting adrenal lesions in patients with MEN 1, and FDG PET is capable of characterising malignant potential.