Altered responses of plasma 18-hydroxycorticosterone and aldosterone to angiotensin II and adrenocorticotropin in patients with a 18-hydroxycorticosterone-producing tumor.

Plasma 18-hydroxycorticosterone (18-OHB) and aldosterone responses to angiotensin II (AII) and ACTH were examined in 2 patients with a 18-OHB-producing tumor (18-OHBPT) versus those in 8 patients with a aldosterone-producing adenoma (APA), 7 patients with low renin essential hypertension (LREH) and 10 normal subjects. Plasma 18-OHB and aldosterone levels and the 18-OHB: aldosterone ratio were high in patients with an APA and normal in patients with LREH. In patients with a 18-OHBPT, plasma 18-OHB and aldosterone levels were high and normal, respectively, resulting in a 2-fold greater 18-OHB: aldosterone ratio than that in patients with an APA. Patients with an APA had a blunted response of plasma 18-OHB and aldosterone to AII and a supranormal response of these corticoids to ACTH. Patients with LREH had a supranormal response of plasma 18-OHB and aldosterone to AII and a normal response of these corticoids to ACTH. In patients with a 18-OHBPT the responses of both plasma 18-OHB and aldosterone to AII and ACTH closely resembled those in patients with an APA but not in patients with LREH. These data suggest that 18-OHBPT may be a variant of aldosteronomas, producing a large amount of 18-OHB and a small amount of aldosterone.