[Malignant adrenal cortex carcinoma revealed by an isolated picture of primary hyperaldosteronism].

Adrenocortical carcinoma (ACC) is a rare disorder with an estimated incidence of only 0.023 percent of all malignancies. In most cases, Cushing's syndrome and virilization or feminization due to abnormal steroid production by the tumor rapidly lead to the diagnosis. Occasionally, the tumor produces an excessive amount of mineralocorticoids only and ACC can be revealed by an isolated syndrome of primary aldosteronism. Out of 100 cases of tumoral primary aldosteronism studied from 1977 to 1987, we observed 4 ACC and 96 Conn's adenomas (CONN). When primary aldosteronism was diagnosed, ACC and CONN had same clinical features, although hypokalemia in ACC was more profound: 2.2 +/- 0.76 mmol/l (1.4 to 3.2) compared to 2.9 +/- 0.5 (1.6 to 4.2) in CONN. Mean supine plasma aldosterone levels, plasma renin and aldosterone responses to the upright posture or to serum saline infusion, cortisol at 8 a.m. were not different in patients with ACC from those observed in patients with CONN. 24 hours urinary cortisol excretion and 17-ketosteroids excretion were highly increased in three out four patients with ACC. Clinical, biological and hormonal investigations were therefore not sufficient to diagnose malignant tumoral primary aldosteronism. Systematic computed tomographic scanning allowed to differentiate carcinomas from adenomas on the following criteria: ACC showed enlarged tumor size that was always above 30 mm in diameter, whereas the largest CONN measured 20 mm.ACC appeared as an heterogeneous tumor with the presence of internal calcifications in each case of ACC, that were diagnosed both on ultrasound and CT scan, whereas none of the CONN showed any calcification, using the same screening procedure.(ABSTRACT TRUNCATED AT 250 WORDS)