Intravascular papillary endothelial hyperplasia

Intravascular papillary endothelial hyperplasias, also known as Masson tumors, are rare non-neoplastic vascular proliferation.

Clinical presentation

Patients usually present with an enlarging soft tissue mass ¹.

Pathology

The lesion is a reactive process characterized by endothelial cell proliferation in the setting of venous stasis commonly associated with thrombosis. The pure form consists of an organized thrombus limited to the vascular lumen. The mixed form arises in the setting of a pre-existing vascular lesion such as hemangioma.

Radiographic features

MRI

Lesions are most commonly located in subcutaneous soft tissues and associated with a visible origin vessel. They are usually small (<2 cm), well-defined, round or oval, and heterogeneous in signal ^1-6. 

• T1: iso- to slightly hyperintense, with nodular foci of high signal intensity
• T2: hyperintense peripherally, with nodular foci of low signal intensity
• T1 C+: peripheral/septal or central enhancement

Treatment and prognosis

The treatment is surgical resection. The pure form of intravascular papillary endothelial hyperplasia carries no risk of recurrence when completely resected.

Differential diagnosis

• angiosarcoma