A 5-year-boy has developed features that suggest puberty over the past 6 months. On physical examination, the boy has secondary sex characteristics, including pubic hair and enlargement of the penis. Which of the following morphologic features is most likely to be seen in his adrenal glands?

Adrenogenital syndrome can lead to precocious puberty, which is most commonly associated with a deficiency of 21-hydroxylase. The lack of this enzyme reduces cortisol production, driving corticotropin production, which leads to adrenal hyperplasia and the production of sex steroid hormones. Bilateral adrenal cortical atrophy is typically seen in cases of Addison disease or after long-term exogenous glucocorticoid therapy. A nodule in the adrenal cortex that has zona glomerulosa cells produces primary hyperaldosteronism; if it has zona fasciculata cells, it produces Cushing syndrome. Most adrenal nodules are nonfunctional and incidental findings. A nodule in the adrenal medulla, if functional, produces catecholamines, and older patients with such nodules have hypertension. Medullary atrophy is rare but might result from infections or toxins. Medullary hyperplasia is uncommon but could also produce catecholamines.