Autoimmune pancreatitis mimicking pancreatic tumor
A 60-year-old male is presented with abdominal pain. On CT scan, a 70 × 66 × 48 mm' lesion was identified in the tail of the pancreas. Repeated aspiration demonstrated no malignancy, tumor markers were within the normal range. Control imaging studies showed enlargement of the mass, infiltrative growth, venous compression and appearance of a pathologic lymph node, suggesting a malignant process, therefore we decided surgical exploration (Fig. ). A solid, malignantly appearing lesion was identified in the body and tail of the pancreas, infiltrating the splenic hilum and transverse colon. A pylorus-preserving total pancreatectomy with splenectomy and extended right hemicolectomy was performed with an uneventful postoperative recovery (Fig. ).\nOn histological examination, both lesions contained elongated spindle cells, infiltration of plasma cells, lymphocytes, histiocytes and eosinophilic granulocytes. There was no evidence of malignancy. Large number of plasma cells were IgG positive, and 40% of the cells were IgG4 positive (Fig. ).\nLaboratory tests proved an elevated IgG4 level (2.4 g/l).