title: Intravascular papillary endothelial hyperplasia involving the synovium.
abstract: To our knowledge, this is the first reported case of intravascular papillary endothelial hyperplasia occurring in the synovium. The patient, a 16-year-old boy, presented with pain and hemarthrosis of the knee in the absence of known trauma. The lesion arose within a subsynovial varix and episodically bled with the intra-articular hemorrhage and reactive synovial changes producing the patient's symptomatology. The clinical, pathologic, and ultrastructural features of the lesion are summarized from a review of the literature, and the differential diagnosis of hemarthrosis with a hemosiderotic synovitis is discussed.
authors.affiliation: Department of Pathology, Harvard Medical School, Boston, MA.
authors.forename: J H
authors.initials: JH
authors.lastname: Eichhorn
authors.forename: A E
authors.initials: AE
authors.lastname: Rosenberg
mesh_terms: D000293:Adolescent; D003937:Diagnosis, Differential; D004727:Endothelium / Q000473:pathology; D006390:Hemangioendothelioma / Q000175:diagnosis / Q000473:pathology*; D006395:Hemarthrosis / Q000175:diagnosis; D006801:Humans; D006965:Hyperplasia / Q000175:diagnosis / Q000473:pathology; D007719:Knee Joint; D008297:Male; D013584:Sarcoma, Synovial / Q000175:diagnosis / Q000473:pathology*; D013583:Synovial Membrane / Q000473:pathology*; D009626:Terminology as Topic