High-grade myofibroblastic sarcoma in the liver: A case report.

Only two cases of myofibroblastic sarcoma in the liver have been reported in the literature. Here, we report the case of a male patient with high-grade myofibroblastic sarcoma mimicking echinococcosis in the liver. The 25-year-old male patient complained of right upper quadrant swelling pain for one week and was initially diagnosed with echinococcosis. He was then scheduled for an exploratory laparotomy. During the operation, a huge mass exceeding 16 cm in diameter was found to occupy nearly the entire right trisegment of the liver, with a clear boundary and a round shape, and the mass was resected by right hepatic trisegmentectomy. Immunohistochemical staining revealed that the tumor tissue was positive for desmin, α-smooth muscle actin, CD56, and vimentin and negative for ALK-1, myogenin, calponin, β-catenin, S100, and glypican-3, with a Ki-67 (MIB-1) index of approximately 20%. Based on the histological manifestations and immunohistochemical staining, a diagnosis of myofibroblastic sarcoma was established. The postoperative recovery was uneventful. There was no evidence of recurrence or metastasis through the last follow-up, 6 mo after surgery, despite a lack of postoperative chemotherapy or radiotherapy. To the best of our knowledge, the present case is the first reported case of high-grade myofibroblastic sarcoma in the liver, and it is also the first reported case in a male patient.