A Case of Insulinoma Presenting With Difficulty Awakening and Prolonged Sleep

We present a case of insulinoma in a 25‐year‐old man with difficulty awakening and prolonged sleep. Despite sleeping for 7–8 h daily, the patient reported recurrent episodes of being unable to wake up in the morning. Initial treatment with a melatonin receptor agonist and mianserin was ineffective, prompting his referral to our institution. Laboratory tests revealed hypoglycemia (45 mg/dL), while polysomnography showed mild obstructive sleep apnea with increased delta waves in the early morning. At the end of polysomnography, he was poorly responsive, and his blood glucose level was 20 mg/dL; his consciousness improved after intravenous glucose administration. Further investigation revealed insulinoma in the pancreatic head. The patient underwent robot‐assisted pancreaticoduodenectomy. Postoperatively, follow‐up polysomnography demonstrated a significant improvement in sleep architecture, and his symptoms resolved. This case highlights the potential for serious underlying conditions, such as insulinoma, to present with nonspecific symptoms such as sleep‐related problems.