What happened, in summary

A 63-year-old woman had Stage IVA lung adenocarcinoma, classified as T3N2M1b, with spread to the abdominal wall and brain. Testing found no EGFR, ALK, ROS1, or BRAF alteration. She received whole-brain radiotherapy and 6 cycles of carboplatin, pemetrexed, and bevacizumab, but the cancer progressed. She then began nivolumab every 14 days and remained on it for about 1 year.

Nivolumab first caused thyroid inflammation with a brief overactive phase, followed by hypothyroidism. Levothyroxine 150 mcg daily was started. Three months later, she was admitted after more than 1 month of worsening fatigue, cough, muscle aches, vomiting, poor intake, and a 10-pound weight loss. Her abdominal cancer mass was described as stable on examination.

The clinical picture supported nivolumab-related inflammation of the pituitary gland, causing central adrenal insufficiency and low sex-hormone signaling. MRI showed a partially empty sella, consistent with later-stage pituitary inflammation. She was discharged on prednisone 80 mg daily with a taper to 15 mg maintenance. Levothyroxine was restarted at 100 mcg daily, and later thyroid tests normalized. Close endocrine follow-up was planned for continued hormone monitoring.