Adrenal lesions in patients with extra-adrenal malignancy - benign or malignant?

Background. Adrenal lesions in patients with extra-adrenal malignancy can be part of disseminated tumour disease, but may also be incidental, benign finding. Strict characterisation is therefore crucial, and may have profound effects on patient management. Purpose. To prospectively characterise and follow-up adrenal lesions in patients with extra-adrenal malignancy, stratified into those with past or concurrent malignancy, with or without metastases. Material and methods. All incidentally detected adrenal lesions identified at cross-sectional imaging during 18 months in a defined geographical region were prospectively reported. All adult oncologic patients with adrenal lesions were subjected to biochemical work-up and dedicated adrenal imaging for lesion characterisation, including a two year follow-up. Results. Benign adrenal lesions were found in 74% (29/39) of patients who had a history of extra-adrenal malignancy, in 53% (57/108) of those with concurrent extra-adrenal malignancy without metastatic disease and in 25% (27/109) in those with signs of metastatic disease. Conclusion. An adrenal lesion occurring in a patient with past malignancy has a high likelihood of representing a benign lesion, and even in patients with present signs of malignant disease at least one fourth to one half of such lesions are benign. Dedicated adrenal imaging including computed tomography attenuation measurements with wash-out characteristics, in addition to biochemical testing for adrenal dysfunction, is highly recommended in these cases, especially in patients without any other signs of metastatic spread.