Adrenal Scintigraphy in Primary Aldosteronism Caused by an Aldosterone Producing Adenoma

Adrenal scintigraphy with 131I-19-iodo-cholesterol was performed in 13 hypertensive patients with biochemical disturbances suggesting an aldosterone-producing adenoma. The actual presence of an adenoma was subsequently confirmed in all cases. An asymmetrical tracer uptake (lateralization) was seen in 7 patients and in 6 of these the adenoma was located in the adrenal with the higher uptake. In one patient a large necrotic tumour was not visualized and a faint contralateral accumulation was wrongly taken to represent a tumour. In 6 patients the scintigram was non-lateralizing. In these highly selected patients a lateralizing scintigram had a high diagnostic specificity and at present adrenal scintigraphy should be the method of first choice in the preoperative side prediction. However, the sensitivity is low: a non-lateralizing scintigram does not exclude the presence of an aldosterone-producing adenoma.