A case report: Masson’s tumor (intravascular papillary endothelial hyperplasia) of the abdominal cavity

Intra-abdominal Masson's tumor is exceedingly rare, and its imaging characteristics have not been systematically defined. In this report, we describe a surgically confirmed case of intra-abdominal Masson's tumor and place particular emphasis on its radiological features, including a well-circumscribed hyper vascular mass with progressive enhancement but without overt signs of malignancy. Despite these suggestive imaging findings, the definitive diagnosis continues to depend on histopathological assessment combined with immunohistochemical staining. By presenting this case, we hope to raise awareness of this benign yet deceptive vascular lesion and highlight that a pattern of progressive enhancement in the absence of malignant imaging features may prompt consideration of Masson's tumor in the differential diagnosis, thereby facilitating earlier and more accurate diagnosis.