Pembrolizumab-Induced Adrenal Crisis Indicated by Increased 18F-Fluoro-D-Deoxyglucose Uptake in Bilateral Adrenal Glands Prior to Onset.

We present a case of adrenal crisis induced by pembrolizumab in a 51-year-old female patient diagnosed with cervical cancer (cT2bN1M1, cStageIVB). Immune checkpoint inhibitors are known to trigger serious immune-related adverse events (irAEs), such as primary adrenal insufficiency. The patient exhibited nonspecific symptoms such as loss of appetite, fever, and shock, indicating pituitary and adrenal insufficiency attributed to pembrolizumab. 18F-fluoro-D-deoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT), performed four days prior to admission, had revealed increased diffuse FDG uptake in bilateral adrenal glands, suggesting potential adrenal crisis. This case underscores that those PET/CT findings may represent an initial indicator of following adrenal irAEs, facilitating early diagnosis and intervention.