Inflammatory Myofibroblastic Tumor of Liver Masquerading as Focal Nodular Hyperplasia in a Patient with Non-Cirrhotic Portal Hypertension and Biliary Pancreatitis.

Inflammatory myofibroblastic tumor (IMT) is a rare lesion of undetermined pathogenesis characterized by proliferation of spindled myofibroblast cells in a collagenized inflammatory background. It is usually benign but may show local infiltration or, in rare cases, metastasis. IMT has been observed in almost all solid organs; however, involvement of liver is exceptional. Its symptoms and radiological findings can mimic malignancy and pose diagnostic difficulties. The authors report the case of a 43-year-old woman with non-cirrhotic portal hypertension and gall stone induced acute pancreatitis having a mass in the right lobe of the liver which was initially diagnosed as focal nodular hyperplasia on imaging but proved to be inflammatory myofibroblastic tumor on pathological and immunohistochemical examination. The lesion resolved with conservative management without the need for surgical intervention.