Background. Accessory spleen is the human growth anomaly, which appears in embryogenesis and frequently becomes an accidental finding during prophylactic medical examination. Pancreatic tail — the second frequent localization after the splenic hilus. Intrapancreatic accessory spleen can mimic the pancreatic tumor. Aim. To demonstrate case series of intrapancreatic accessory spleen in course of differential diagnostic with pancreatic neuroendocrine tumor and metastasis of renal — cell cancer. Material and methods. Three patients with intrapancreatic accessory spleen were observed in abdominal department №1 A.V.Vishnevsky Institute of Surgery, — two females and one male. Results. Two patients were surgically treated: in the first case basing on preoperative anamnesis and diagnostic data diagnosis of renal – cell cancer metastasis was established, in the second case – nonfunctional pancreatic neuroendocrine tumor. In both cases robotic distal pancreatectomy was performed. There were no conversions. Postoperative recovery was accompanied by clinicaly not relevant pancreatic fistulas, which didn’t increase length of hospitalization. In the third case during CT and MRI diagnosis of intrapancreatic accessory spleen was determined. Surgical treatment wasn’t performed. Control examination showed an absence of dynamic of characteristics and growth. Conclusion. Described cases demonstrate difficulty of differential diagnostics of tumor — like mass. Neuroendocrine tumors, renal — cell cancer metastases, solid pseudopapillary neoplasms and accessory spleen can have similar CT-characteristics. In appearance of differential diagnostic difficulties minimally invasive surgical treatment has to be performed.