S2429 Primary Splenic Angiosarcoma With Liver Metastasis: A Rare Cause of Portal Hypertension

Abstract

INTRODUCTION: Primary splenic angiosarcoma (PSA) is an extremely rare neoplasm that commonly metastasizes to the liver. We present a patient with abdominal pain and abnormal splenic imaging, found to have PSA with hepatic metastasis causing portal hypertension. CASE DESCRIPTION/METHODS: A 34-year-old female with no significant history presented with a 1-month history of progressively worsening left-sided upper abdominal pain. CT showed a heterogeneous area of low-attenuation in the spleen measuring 7.5 × 9.5 cm concerning for a large splenic infarct and cirrhotic liver morphology. Abdominal ultrasound with elastography revealed F4 fibrosis compatible with hepatic cirrhosis with patent hepatic vasculature. MRI/MRA for further evaluation of liver and splenic vasculature showed a hemorrhagic mass within the spleen, with no evidence of hepatic steatosis or fibrosis. Subsequent liver biopsy with portal pressures revealed nodular regenerative hyperplasia and portal hypertension. Free hepatic vein pressure was 20 mmHg, wedged hepatic vein pressure was 36 mmHg, and hepatic venous pressure gradient was 16 mmHg. Given concern for lymphoma, she underwent a PET/CT scan which showed a hypermetabolic 8.6 cm mass in the spleen with central necrosis, highly concerning for neoplasm and diffusely increased hypermetabolism in the liver. She subsequently underwent splenectomy and repeat liver biopsy. Pathology was consistent with high-grade angiosarcoma in the spleen and the liver. The patient was diagnosed with PSA with metastasis to the liver complicated by portal hypertension. DISCUSSION: Primary splenic angiosarcoma (PSA) is an extremely rare neoplasm with a reported incidence of 0.15–0.26 cases per million. The majority of patients present with distant metastases, most commonly in the liver with an incidence of 70%. Pathogenesis remains unclear. Possible causes include ionizing radiation, arsenic, vinyl chloride, and chemotherapy for lymphoma, versus originating from previously existing benign tumors, such as hemangioma or hemangioendothelioma. Upper abdominal pain is the most common clinical manifestation. There has only been 1 reported case of primary splenic hemangiosarcoma associated with portal hypertension in the literature. There are no guidelines for diagnosis of PSA, and our patient was diagnosed after splenectomy, which is the primary treatment for PSA without metastasis. In metastatic PSA, the role of adjuvant therapy is unclear with no treatment consensus, and prognosis is poor.Figure 1.: PET/CT with large, hypermetabolic region in the medial spleen measuring approximately 7.6 × 8.6 cm. No discrete lesions are seen in the liver; however, there is abnormally increased background activity.Figure 2.: Immunohistochemical stain for CD31 highlights abnormal vascular proliferation in liver.Figure 3.: Spleen with proliferation of abnormal vessels and abnormal endothelial cells.