Analysis of misdiagnosis and mistreatment of epidermoid cyst in intrapancreatic accessory spleen

Objective To investigate the imaging characteristics and the cause for the misdiagnosis and mistreatment of epidermoid cyst in intrapancreatic accessory spleen (ECIPAS) in order to improve the accuracy of preoperative diagnosis. Methods The clinical and imaging data of 8 patients with ECIPAS confirmed by pathology in Zhejiang Provincial People′s Hospital between June 2008 and February 2018 were collected. The reason for doctor visit included CA19-9 elevation (n=1) and pancreatic occupying mass (n=9) during physical examination and no obvious symptoms were reported. CT and MRI imaging features, diagnosis and treatment were analyzed. Results The lesions in 8 cases of ECIPAS were all located in the tail of the pancreas and were cystic and solid. The lesions in 3 cases were mainly cystic and the cystic wall was linear, whose CT density, MRI signal and enhancement pattern cannot be compared with those of the spleen. Solid components can be seen in 5 cases, and the CT density or MR signal of the solid part was similar to that of the spleen. After enhancement, the solid part at the artery stage was uniformly enhanced and the enhancement degree was higher than that of the pancreas. Similar to the spleen, it was uniformly enhanced at the portal vein stage and the enhancement degree of the spleen was consistent. All 8 patients were diagnosed with pancreatic neoplastic lesions before surgery, and 1 patient had pancreatic fistula and peripancreatic necrosis after surgery. Postoperative pathology confirmed the diagnosis of ECIPAS. Conclusions Improving the radiologists and clinicians′ cognition of the imaging manifestations of ECIPAS can improve the accuracy of preoperative diagnosis and avoid unnecessary surgery due to misdiagnosis. Key words: Pancreas; Accessory spleen; Epidermal cyst; Tomography, X-ray computed; Magnetic resonance imaging