A case of acute cholecystitis with abnormally high CA19-9.

Background: CA19-9 is strongly expressed in malignant tumors of the digestive system and is widely used as a marker for gastrointestinal cancer. In this report, we describe a case of acute cholecystitis in which CA19-9 was markedly elevated.

Case Presentation: A 53-year-old man was admitted to our hospital with a diagnosis of acute cholecystitis after being referred to our hospital with a chief complaint of fever and right hypochondrial pain. CA19-9 was abnormally high at 17,539.1 U/ml. Although the possibility of malignancy was considered, there was no obvious malignant lesion on imaging; the patient was diagnosed with cholecystitis, and laparoscopic cholecystectomy was performed the day after admission. The surgical specimen showed no malignant findings either grossly or in the final pathological examination. There were no complications in the patient's postoperative course, and he was discharged from the hospital on the third postoperative day. CA19-9 level quickly returned to within normal range after surgery.

Conclusions: In acute cholecystitis, CA19-9 levels exceeding 10,000 U/ml are very rare. We report a case of acute cholecystitis without malignant findings despite a high CA19-9 level.