2018 Volume 33 Issue 5 Pages 847-853
A 47-year-old Japanese female underwent mastectomy for right breast cancer 2 years earlier and started tamoxifen 2 months later. Twenty-seven months after starting tamoxifen, she presented with left abdominal pain. She was diagnosed with acute pancreatitis, with pancreas swelling and fat necrosis in the left anterior pararenal space seen on CT scan. Treatment included nothing by mouth, intravenous fluids and nafamostat mesilate infusion, 20mg/day. She recovered and was discharged on the 13th hospital day. Serum triglyceride levels during the hospitalization were remarkably high, as high as 5512mg/dl, and we suspected that hypertriglyceridemia secondary to tamoxifen was the cause of the acute pancreatitis. The tamoxifen was withdrawn immediately, and we followed the patient's serum triglyceride levels after stopping tamoxifen and after discharge. At 4 months post-discharge, her triglyceride level had decreased to normal. Tamoxifen-induced hypertriglyceridemia is rare, but may occasionally cause severe pancreatitis. The serum triglyceride level of patients taking tamoxifen should be closely monitored, and when hypertriglyceridemia is detected, it is necessary to be aware of the risk of pancreatitis.