CT-scan, MRI and image-guided FNA cytology of incidental adrenal masses

Aim: The aim of this study was to compare the usefulness of computed tomography (CT)-scan, magnetic resonance imaging (MRI), and fine-needle aspiration (FNA) cytology in patients with incidentally discovered adrenal masses. Patients and methods: Thirty-four consecutive patients (six men and 28 women, median age of 47 years, range 26–80) with non-functioning adrenal masses of 2 cm or more (median 3.5 cm, range 2–9) were studied. All patients underwent CT-scan, MRI, and image-guided FNA cytology using spinal-type narrow-gauge needles prior to further procedures. Nineteen patients underwent adrenalectomy. Results: Final pathology showed 13 benign adrenal lesions, four adrenocortical carcinomas, and two unsuspected adrenal metastases. Fifteen patients who did not have surgery were considered definitively as having benign adrenal lesions since the mass was unchanged on CT-scans performed during follow-up. The sensitivity, specificity, and positive predictive value were 66.7, 85.7, and 50.0%, for CT-scan, 83.3, 92.9, and 71.4% for MRI, and 83.3, 100, and 100% (p<0.05) for FNA cytology, respectively. Conclusions: Image-guided FNA cytology is a safe and sensitive procedure that may reveal unsuspected adrenal malignancies, and should be performed in all patients with incidentally discovered adrenal masses of more than 2 cm in size.