Pancreatic Hamartoma Difficult to Diagnose Preoperatively.

Abdominal ultrasonography in a 70-year-old woman showed a hypoechoic mass, 14 mm in diameter, in the pancreatic body. Computed tomography showed a mass with contrast effect in the pancreatic body. Test results for endocrine factors or tumor markers were normal. The initial consideration was nonfunctional pancreatic neuroendocrine tumor. Over 8 years of monitoring, the tumor diameter increased to 18 mm, until pancreatic tumor enucleation was performed. The postoperative diagnosis was pancreatic hamartoma, a rare type of benign pancreatic tumor. The preoperative diagnosis of pancreatic hamartoma is difficult, but consideration must be given to the possibility of hamartoma when encountering pancreatic tumors.