Incidental Diffuse Splenic Polyangiomatosis With Long-Term Radiologic Stability: A Case Report.

Splenic polyangiomatosis is an exceptionally rare benign vascular proliferation characterized by multiple vascular channels that may replace large portions of the splenic parenchyma. Most reported cases are discovered incidentally, as the condition is often asymptomatic and identified during imaging performed for unrelated reasons. We report the case of a 46-year-old asymptomatic woman in whom splenomegaly was detected during a routine clinical evaluation. Cross-sectional imaging with CT and MRI revealed marked splenomegaly with innumerable solid and cystic nodular lesions replacing more than 80% of the splenic parenchyma, with stable radiologic features over several years. A comprehensive diagnostic approach integrating clinical findings, laboratory evaluation, and multimodality imaging supported the diagnosis of benign splenic polyangiomatosis. This case underscores the importance of clinicoradiologic correlation in distinguishing this rare benign entity from other vascular, infectious, inflammatory, infiltrative, and malignant causes of multinodular splenic disease, and highlights the relevance of long-term imaging stability in guiding conservative management.