This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Parathyroid & Adrenal Glands, Subject name: Surgery
Incidentally findings, in CT scan, a 3cm adrenal mass, which of the following is NOT- done 
Select and explain. 
A. Adrenalectomy, B. Dexamethasone suppression test, C. Measurment of catecholamines, D. Midnight plasma cortisol
A: Adrenalectomy
Answer: A: Adrenalectomy 
Explanation: (Adrenalectomy) (816- B&L 24th) (812-Baily &Love 25th)* A unilateral non functioning adrenal mass greater than 4cm in diameter is an indication for adrenalectomy. The patient with a mass smaller than 4cm in diameter should undergo repeat CT/MR1 -4-6 months after the previous examinationINVESTIGATIONSFunctioning adrenal tumourA malignant adrenal mass1. 2 x 24 hour urine collection for catecholamines and metanephrines** FNAC* Primary adrenocortical carcinoma -2. Plasma urea and electrolytes, plasma aldosterone and reninIncidentalomas of 4cm or more in diameter carry an increased risk of malignancy3. Basal a-m and midnight plasma cortisol, blood glucose, DHEAS4. 1 mg overnight dexamethasone suppression test*