[Primary splenic angiosarcoma: A rare vascular lesion at the diagnostic boundaries].

Primary splenic angiosarcoma is a rare malignant vascular tumour, accounting for less than 1% of all sarcomas and only a few hundred cases reported in the literature. Diagnosis relies on the correlation of clinical, radiological, and histopathological findings. The disease progresses rapidly, and its prognosis is particularly poor. We report the case of a 64-year-old woman admitted to the emergency department for abdominal pain, fatigue, and weight loss. Imaging revealed a heterogeneous splenomegaly complicated by capsular rupture, which led to splenectomy. Macroscopically, the spleen was enlarged, haemorrhagic, and necrotic. Histopathological examination showed a proliferation of atypical endothelial cells forming irregular vascular spaces, confirmed immunohistochemically by the expression of ERG, CD31, and CD34, as well as CD68 and CD163, an immunophenotype that, in the presence of less pronounced atypia, could have been mistaken for a littoral cell angioma. This case illustrates the morphological heterogeneity and broad differential diagnosis of splenic angiosarcoma, particularly in its well-differentiated forms. It also highlights the aggressive nature of these tumours despite non-specific clinical presentation, the need for extensive sampling and appropriate immunohistochemical panel, and the current limitations of molecular approaches and the effectiveness of therapies in this entity.