A hepatic solitary fibrous tumor with giant cells and a review of the literature.

BACKGROUND: Solitary fibrous tumor (SFT) is a rare mesenchymal tumor usually occurring at the pleura. Primary hepatic SFT presents at the liver is extremely rare, and its nonspecific clinical-biological findings cause a considerable difficulty in differentiation from other hepatic tumors. CASE PRESENTATION: We reported a uncommon case of primary hepatic SFT, which was pathologically characterized by abundant multinucleated giant cells. A man in his 60 s was admitted for a long-standing right upper abdominal pain (more than several months). Magnetic resonance imaging (MRI) scan revealed a mass in the liver. A right hemihepatectomy was performed and the pathological diagnosis revealed a tumor consisting of spindle-shaped tumor cells arranged in various forms with the presence of sparsely scattered numerous giant cells. Based on immunohistochemical staining (STAT6 + /CD34 +) and the WHO risk stratification criteria (high-risk category, score 7), the tumor was diagnosed as primary hepatic malignant SFT with giant cells. The patient recovered after the surgery and was administrated to regular lenvatinib treatment without recurrence for a course of 25 months. CONCLUSION: The hepatic SFT with giant cells (SFT-gc) is an exceedingly rare variant of primary hepatic SFT. Because of its anatomic atypia, careful distinction should be made from other frequent hepatic tumors, and a high index of suspicion is essential for accurate histopathological diagnosis.