Abstract
Diagnosing leiomyosarcomas of the splenic vein is challenging, and a treatment strategy has not yet been established for this condition. We herein report the case of a 45-year-old female patient with a history of retinoblastoma who underwent pancreatosplenectomy for a primary leiomyosarcoma originating from the splenic vein and transcatheter arterial chemoembolization for metastatic hepatic lesions observed 5 months postoperatively. An initial medical check-up using abdominal ultrasound revealed a 40-mm mass behind the pancreatic tail. Imaging tests revealed a well-circumscribed mass compressing the pancreas posteriorly, without invasion into the pancreatic duct. The splenic vein was torn, with the epiploic veins developed as collateral blood vessels, which was an atypical finding for carcinoma. The patient was followed up regularly. At 5 years after the first visit, an abdominal ultrasound showed that the mass had increased in size to 50 mm, and had developed into a tumor embolus within the splenic vein, causing an obstruction of the vessel. Pancreatosplenectomy was performed due to suspicion of malignancy. The final diagnosis was leiomyosarcoma arising from the splenic vein. The patient was discharged on postoperative day 15 and was followed up regularly thereafter. Imaging studies performed 5 months postoperatively revealed four hepatic lesions. The hepatic masses were histologically diagnosed as metastatic leiomyosarcomas, and transcatheter arterial chemoembolization was performed using epirubicin. Since then, regular follow-ups have been conducted without observed recurrence. Leiomyosarcoma of the splenic vein is exceedingly rare, and the number of reported cases is not sufficient to establish clinical guidelines. Therefore, it is crucial to collect more reports on the occurrence and treatment of this disease.