Which condition is associated with corticotropic adenoma?

Corticotropic adenomas, also known as corticotroph adenomas, are pituitary tumors that secrete adrenocorticotropic hormone (ACTH). This hormone stimulates the adrenal glands to produce cortisol, which is the primary glucocorticoid responsible for regulating various metabolic processes and responding to stress.

In the context of the question, Cushing's syndrome is directly linked to the effects of excess cortisol production. When a corticotropic adenoma secretes ACTH inappropriately, it can lead to hypercortisolism, which manifests as Cushing's syndrome. This condition presents with a range of symptoms, including weight gain, hypertension, moon facies, and hyperglycemia, among others.

In contrast, the other conditions listed are associated with different causes. Acromegaly and giantism are related to excess growth hormone, typically due to growth hormone-secreting pituitary adenomas, while infertility can result from various hormonal imbalances but is not directly linked to the secretion of ACTH by corticotropic adenomas. Therefore, the association of corticotropic adenomas with Cushing's syndrome makes this the most appropriate answer.