Endocrine Abstracts

Adrenal tumours are among the most common human neoplasias and comprise a wide range of pathologies from benign non-secretory adenomas (leave-me-alone lesions) to life threatening adrenocortical cancer (ACC) requiring early detection and treatment. For the patient, the discovery of an adrenal mass inevitably raises the question whether the lesion is malignant. Current strategies to answer this question are based upon tumor size, imaging characteristics in CT or MRI and follow-up imaging. Fine needle biopsy has limited diagnostic utility and carries the risk of needle track metastasis in ACC.

However, modern functional imaging holds the potential to fully and non-invasively characterize adrenal lesions already at the time of discovery (metomidate scintigraphy, ¹⁸F-FDG PET, ¹⁸F-L-DOPA PET) thereby reducing uncertainty and follow-up visits. More specifically, high uptake in ¹⁸F-FDG-PET in combination with a positive ¹²³I-Iodometomidate scan indicates a very high likelihood of ACC and warrants surgery. While hormonally active benign adrenal lesions are removed via a minimal invasive approach, open surgery is currently advocated for potentially malignant lesions. However, data from the German ACC registry indicate that also in ACC (diameter <10 cm) a laparoscopic approach is safe in the hands of an experienced surgeon. In ACC, removal of the tumour is often not curative as tumour recurrence is frequent. High expression of GLUT1 or SF1 in the tumour is associated with an increased risk of tumour recurrence and reduced overall survival. Adjuvant treatment strategies consisting of mitotane and tumour bed irradiation may prolong disease-free survival. Management of advanced disease is still frustrating with a median survival of only 12 months using current treatment protocols. However, individualized treatment, new targets like IGF1 receptor or SF1, and the use of ¹³¹I-Iodine-metomidate may significantly improve outcome.