Pigmented villonodular synovitis (PVNS) is a rare benign proliferative disorder of synovium most commonly affecting the knee joint. It is often progressive leading to degeneration and destruction of the affected joint. The disease presents with joint pain, swelling, stiffness and locking. Surgical synovectomy is the treatment of choice that can be performed either arthroscopically or through open procedure.
A 25-year-old male presented in OPD with painful swelling of right knee joint. On examination, there was a small (3×5 cm) circumscribed lump on the lateral aspect of the right knee. It was firm in consistency and disappeared on knee extension. Distal pulse and neurological examination was unremarkable. Radiograph was normal however, magnetic resonance imaging showed a radiodense lesion.