SHM Converge Scientific Abstract ePoster Gallery-Pembrolizumab-Induced Hypophysitis in the Setting of Renal Cell Carcinoma

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This case report describes a 55-year-old woman with renal cell carcinoma treated with pembrolizumab monotherapy after nephrectomy who developed recurrent weakness, orthostatic hypotension, nausea, vomiting, food aversion, hypoglycemia, and hyponatremia. She had been hospitalized nine times for similar unexplained symptoms before the endocrine cause was identified.<br /><br />During her admission, low morning cortisol and low ACTH suggested secondary adrenal insufficiency. A cosyntropin stimulation test showed a rising cortisol response, supporting a central cause rather than primary adrenal failure. Elevated prolactin prompted MRI evaluation of the sella, which showed nonspecific anterior pituitary changes consistent with hypophysitis and no prolactinoma. Endocrinology concluded that the most likely cause was pembrolizumab-induced hypophysitis, despite the drug having been stopped about five months earlier. Her prolactin elevation was attributed to sertraline rather than pituitary tumor.<br /><br />She was treated with IV hydrocortisone and improved rapidly: nausea, vomiting, food aversion, hypotension, hypoglycemia, and hyponatremia all resolved. She was discharged on oral hydrocortisone and continued to do well in outpatient follow-up without recurrence of symptoms.<br /><br />The report highlights that immune checkpoint inhibitors can cause endocrine toxicities, most commonly thyroid dysfunction, while hypophysitis from PD-1 inhibitors such as pembrolizumab is rare. It emphasizes that symptoms may appear even months after treatment ends and that clinicians should maintain a high index of suspicion for adrenal insufficiency and pituitary dysfunction in patients with prior immune checkpoint inhibitor exposure.

Asset Subtitle

Naisarg B. Vanani

Meta Tag

Author List Kassandra M. Ogbodu, Naisarg B. Vanani, Pinky Jha

Category Clinical Vignettes

Concept Immune Checkpoint Inhibitor

Concept Endocrine Immune-Related Adverse Event

Concept Pituitary Toxicity

Concept Hypophysitis

Concept Secondary Adrenal Insufficiency

Concept ACTH

Concept Glucocorticoid Replacement

Distinguished Non-Finalist

Presenter Organization Medical College of Wisconsin

Presenting Author Naisarg B. Vanani

Track Adult

Keywords

pembrolizumab

hypophysitis

secondary adrenal insufficiency

renal cell carcinoma

immune checkpoint inhibitor

ACTH deficiency

hyponatremia

hypoglycemia

orthostatic hypotension

hydrocortisone

Immune Checkpoint Inhibitor

Endocrine Immune-Related Adverse Event

Pituitary Toxicity

Hypophysitis

Secondary Adrenal Insufficiency

ACTH

Glucocorticoid Replacement