Splenic Angiosarcoma and Numerous Liver Metastases Presenting the Kasabach-Merritt Phenomenon

Splenic angiosarcoma is a rare and serious malignancy. We investigated the diagnosis and the suitable treatment strategy for metastatic splenic angiosarcoma with the Kasabach-Merritt phenomenon.

A 76-year-old man was referred because of abdominal discomfort together with anemia, thrombocytopenia, and disseminated intravascular coagulopathy. Contrast-enhanced computed tomography revealed some huge, low-attenuation large splenic tumors and numerous liver tumors. Magnetic resonance imaging showed tumors with low and heterogeneous high signal intensity on T1-weighted and T2-weighted images, respectively. Several splenic tumors contained peripheral hypointense areas on T2WI that demonstrated a signal drop in in-phase compared to opposed-phase chemical-shift T1WI. A percutaneous needle biopsy of liver tumors with needle-tract radiofrequency ablation was performed without bleeding. The patient was pathologically diagnosed as splenic angiosarcoma by several immunohistochemical analyses. We started anticoagulant-fibrinolytic therapy with nafamostat mesylate; however, partial ischemia of the jejunum happened twice, and partial resections and the creation of an ileostomy were performed. The patient has been relatively stable for 3 months with paclitaxel monotherapy followed by oral pazopanib. Kasabach-Merritt phenomenon has been stable during good control of splenic angiosarcoma.

Metastatic splenic angiosarcoma with the Kasabach-Merritt phenomenon might be controlled by accurate diagnosis, precise surgical intervention for digestive organ ischemia, and effective chemotherapy. The Kasabach-Merritt phenomenon is an effective indicator of chemotherapy response. Furthermore, the development and clinical application of new chemotherapies are needed.