Chronic Knee Pain in a Young Adult: Unmasking a Synovial Haemangioma after a Decade

A 21-year-old male presented with complaints of pain in the left knee for the past 10 years. The pain was insidious in onset, persistent, non-radiating, and had worsened over the last two months, particularly during weight-bearing and knee movements, with no identifiable relieving factors. There were no similar symptoms in the contralateral knee. The patient was not diabetic or hypertensive and had no history of smoking, alcohol use, or any significant past medical history. General examination was unremarkable.