R. S. is a 66-year-old female with Cushings syndrome due to an ACTH-producing pituitary tumor. The tumor is readily isolated by imaging, and the patient had an uneventful surgery. When seeing her in follow-up, the AGACNP anticipates
Correct Answer: B
Rationale: The correct answer is B: Transient rebound release of remaining pituitary hormones. After surgical removal of the ACTH-producing pituitary tumor in Cushing's syndrome, there may be a transient rebound release of remaining pituitary hormones due to relief of negative feedback from the tumor. This can lead to a temporary increase in pituitary hormone levels before normalization.
Rationale:
1. Rapid reversal of symptoms with good pituitary function (Choice A) is less likely as it takes time for the pituitary gland to recover and resume normal hormone production post-surgery.
2. Markedly improved dexamethasone suppression test (Choice C) is not expected immediately after surgery as it may take time for the hypothalamic-pituitary-adrenal axis to normalize.
3. Hyponatremia and compensatory SIADH (Choice D) are unlikely post-operatively in Cushing's syndrome as removal of the ACTH-producing tumor should lead to normalization of