Case Report: Primary splenic angiosarcoma: a case report and literature review

Primary splenic angiosarcoma (PSA) is a rare, highly aggressive malignant vascular tumor with nonspecific clinical and imaging findings. We report a 42-year-old man who presented with recurrent left upper abdominal pain after splenic artery embolization for multiple hypervascular splenic lesions with local rupture and hemorrhage. Because symptoms recurred, imaging showed a complex splenic lesion, and the diagnosis remained uncertain, open splenectomy and lysis of intestinal adhesions were performed on March 12, 2024. Intraoperatively, approximately 4000 mL of bloody ascites and active splenic bleeding were found. Pathology showed destruction of the splenic architecture by anastomosing abnormal vascular channels, intraluminal papillary structures, and focal solid areas, with marked atypia, extensive necrosis, a Ki-67 labeling index of approximately 40%, mutant-type p53 expression, and positivity for CD31, FLI-1, and ERG, supporting splenic angiosarcoma. After surgery, the patient was clinically managed as having advanced disease with hepatic and bone involvement and received denosumab, first-line EIM chemotherapy, second-line gemcitabine plus albumin-bound paclitaxel combined with anlotinib, followed by the addition of sintilimab, and subsequent maintenance therapy with anlotinib plus sintilimab. The medical record documented progressive disease after two cycles of EIM therapy and repeated stable disease during later treatment. The formal imaging reports also described mixed objective changes, including partial shrinkage of hepatic lesions at several time points. The last treatment and follow-up date supported by the available records was October 10, 2025. This case suggests that PSA should be considered early when complex vascular splenic lesions are accompanied by splenomegaly, recurrent pain, anemia, and bleeding or rupture risk. Splenectomy can provide both diagnostic and therapeutic value, while individualized multimodal treatment and close follow-up remain central for advanced PSA.