A case of adrenal cortical carcinoma arising from a regularly monitored sub-centimetre adrenal incidentaloma.

Abstract

Approximately 80% of adrenal incidentalomas are benign, and development into adrenal cortical cancer is extremely rare. This is a major reason behind clinical guidelines recommending surveillance of incidentalomas for a relatively short duration of up to 5 years. Surveillance of lesions less than 1 cm is not routinely recommended. A 70-year-old lady was diagnosed with a non-hyperfunctioning 8 mm right adrenal lesion. She underwent annual biochemical and radiological assessment for 5 years before surveillance was extended to 2-yearly intervals. The lesion was stable in size, and radiological characteristics were consistent with a benign adenoma. Seven years after the initial detection of the adrenal lesion, she developed acute abdominal pain. Imaging revealed a 7 cm right adrenal lesion, which was surgically resected and histologically confirmed to be adrenal cortical cancer. She died 1 year later. Clinical guidelines have moved towards a shortened duration of surveillance of incidentalomas. Even though malignant transformation is a rare event, it is possible that this will result in a delayed diagnosis of adrenal cortical cancer, a highly aggressive malignancy with a poor prognosis. To our knowledge, this is the first published case of an adrenal lesion of less than 1 cm developing into adrenal cortical cancer. Adrenal incidentalomas are increasingly common. Clinical practice guidelines exist to aid in differentiating benign and malignant lesions and assessing functional status. Transformation of adrenal incidentalomas to adrenal cortical carcinomas is a rare but recognised event.