CYP11B2 and adenoma: Previous studies, with sample sizes ranging 60–98 subjects, have shown that in unilateral PA, patients with nonclassical adrenal histopathology (i.e. the absence of a CYP11B2-positive adenoma) exhibit a higher incidence of postsurgical disease and increased aldosterone production from the remaining adrenal (8, 10, 12, 13).