Malignant extra-gastrointestinal stromal tumor of the liver: A case report

Extra-gastrointestinal stromal tumors (EGISTs) predominantly occur outside of the gastrointestinal tract, and their biological and histological characteristics are similar to those of GISTs. Primary EGIST occurrence in the liver is extremely rare. The present study reports a case of primary EGIST in the caudate lobe of the liver in a 61-year-old Chinese man. Contrast-enhanced computed tomography revealed a 7.3×5.1-cm heterogeneously enhanced neoplasm with solid and cystic components located in the caudate lobe of the liver. The patient underwent caudate lobe (specifically, Spiegel lobe) resection. Immunohistochemical analysis of the resected tumor revealed a strong positivity for cluster of differentiation (CD)117, discovered on GIST-1 and CD34. Thus, based on the histological and immunohistochemical findings, the final diagnosis was primary hepatic EGIST. Follow up was conducted at 3-month intervals for the first year and 6-months thereafter. The patient was asymptomatic without any sign of recurrence during the follow-up period. Lab tests were in normal range, and no mass was found in CT scan.