ARMC5 expression in adrenocortical nodules. A, Immunohistochemistry of adrenocortical nodules stained for ARMC5. A-I, Nonhyperplastic adrenal tissue, surrounding aldosterone-producing adenoma (no ARMC5 mutations). A-II and A-III, ADT110.01 (with a benign ARMC5 variant) is a 51-year-old male with a 5-year history of hypertension who underwent left adrenalectomy, which revealed a dominant left adrenal nodule 1.1 × 1.0 × 0.7 cm and surrounding hyperplasia. A-IV and A-V, ADT105.2 (with a predicted damaging ARMC5 variant) is a 63-year-old male with a 35-year history of hypertension who underwent left adrenalectomy, revealing a dominant nodule 1.3 × 0.8 × 0.8 cm, surrounded by macro- and micronodular adrenal hyperplasia. A-VI and A-VII, ADT130.01 is 44-year-old male (with a predicted damaging ARMC5 variant) with a 12-year history of hypertension. Computed tomography revealed bilateral adrenal hyperplasia; left adrenalectomy revealed a 1.4-cm dominant nodule with surrounding hyperplasia. B, Western blot analysis of ARMC5 protein in normal adrenal (N) and aldosterone-producing adrenal adenoma from a patient without ARMC5 mutations (ADT201.02) and from a patient with a predicted damaging ARMC5 variant (ADT130.01).