Two case reports of rare diseases occurring in rare parts: splenic vein solitary fibrous tumor and liver solitary fibrous tumor.

Solitary fibrous tumor (SFT) is a rare soft tissue tumor originating from mesenchymal cells. Here we report two new cases of SFT. One case was a 37-year-old female patient whose primary tumor site was located in the splenic vein and the primary tumor resulted in splenomegaly and hypersplenism; its recurred for many times after surgical resection and eventually transferred to the liver, 4 operations were performed during 10 years of follow-up, and the patient is in a good condition right now. The second case was a 54-year-old male patient whose primary tumor site was located in the liver, spleen and left side of the chest wall. We performed two operations to remove these tumors, totally. Six years later, SFT recurred in the liver, given that the tumor was too large to be surgical resected completely, we chose orthotopic liver transplantation (OLT), and no tumor recurred during 6 years' follow-up, he is also in a good condition right now. The reports of these two cases of SFT are exceedingly rare, especially the splenic vein SFT is the first report case, which helps expand the understanding of SFT. Although the current mainstream treatment of SFT is surgical resection, liver transplantation may be a new option treatment for the huge liver SFT. 2021 AME Case Reports. All rights reserved.