Synovial haemangioma of the knee: light and electron microscopic findings

Synovial hemangiohamartomas of the knee joint

Hemangioma or vascular malformation of the synovium is rare and presents a difficult problem in diagnosis and treatment. A long history of joint pain and recurrent non-traumatic hemarthrosis usually draws attention to the hemangioma of the knee joint. The lesion can be seen in two different formations; the synovial hemangioma or the arteriovenous malformation named as hemangiohamartomas, both of which involve the synovium and cause non-traumatic episodes of hemarthrosis. MRI scanning together with arthroscopy is a diagnostic tool to demonstrate the extent and the nature of the lesion. We treated the three patients at different ages. All patients underwent standard radiographic examination, CT scans, MRI and diagnostic arthroscopy. After frozen section taken via arthroscopically, the lesions were excised by arthrotomy. The mean follow-up was 38 months (31-45) and all patients are asymptomatic postoperatively. Three additional cases and a review of the literature are presented because of the rarity of the lesion.

Synovial hemangioma: a report of 20 cases with differential diagnostic considerations

True synovial-based hemangiomas are uncommon lesions and, as such, may enter the differential diagnosis of other lesions encountered more frequently in clinical practice, including pigmented villonodular synovitis and traumatic hemarthrosis. The consultation files of the Armed Forces Institute of Pathology were searched for benign vascular lesions diagnosed as synovial or bursal hemangiomas vascular lesions diagnosed as synovial or bursal hemangiomas submitted between the years 1960 and 1985; 20 cases of synovial hemangioma were identified. The patients ranged in age from 9 to 49 years at the time of presentation (average age, 25 years). Sixty-five percent of the patients were male; 35% were female. Presenting symptoms included pain and swelling (31%), pain alone (31%), and a painless mass (31%). Affected regions included the knee (60%), the elbow (30%), and the finger (10%). In 65% of cases the lesion was confined to the intra-articular synovium; in 30% of cases the hemangioma was located in a bursa adjacent to a joint. One case was located largely within the joint cavity but had an area of extension into the suprapatellar recess. The dominant histologic patterns included cavernous hemangioma (50%), lobular capillary hemangioma (25%), arteriovenous hemangioma (20%), and venous hemangioma (5%). One lesion (which had been incompletely excised) was removed in its entirety 3 months after the initial subtotal resection; otherwise, none of the patients studied developed recurrent disease. The clinical diagnosis of hemangioma was made in 22% of cases, while an initial pathologic diagnosis of hemangioma was reached in 67% of cases. Pathologic differential diagnostic considerations include nonspecific synovitis/bursitis, pigmented villonodular synovitis, nodular synovitis, and organizing hemorrhage. A relationship between synovial hemangioma and pigmented villonodular synovitis was not suggested by this analysis of our material.