Two Discrete Intra-articular Synovial Hemangiomas of a Knee Joint Presenting as Chronic Knee Pain

Synovial hemangioma (SH) is a rare benign soft-tissue tumor of vascular origin. That can be extraarticular, juxta-articular, or intraarticular. The knee joint is the most common joint involved. Symptoms can be variable and diagnosis can be made using magnetic resonance imaging. Differentials can be ruled out by biopsy and the gold standard treatment is complete excision of the lesion.

A 20-year-old male presented to outpatient clinic with a chief complaint of right-sided anterior knee pain for 2 years aggravated for 2 months. Ultrasonography and magnetic resonance imaging showed two discrete intra-articular lesions. The lesion was hypointense on T1W and hyperintense on T2W and STIR sequence that was enhancing on contrast. There were adjoining dilated vessels. With a provisional diagnosis of hemangioma, FNAC was done and then complete excision was done using a medial parapatellar arthrotomy. The patient is doing well at 1-year follow-up.

Knee joint SH is a rare presentation to orthopedic outdoors and has slight female predominance with pre-existing history of trauma. In the present study, both cases were of patella-femoral type (anterior and infra-patellar fat pad). For such lesions, en bloc excision is the gold standard procedure to prevent recurrence, same procedure was followed in our study, and good functional outcome was achieved.