Villonodular Synovitis of the Index Finger: A Case Report

Abstract

Villonodular Synovitis (VNS) is a rare condition characterised by abnormal growth of synovial tissue and accumulation of haemosiderin within joints, tendon sheaths and bursae. While the exact aetiology remains unclear, chronic inflammation is a leading theory. Although VNS typically affects large joints, the present case report highlights the possibility of its occurrence in smaller joints like the index finger. Early diagnosis and surgical intervention are crucial for effective management of VNS. The present case report underscores the importance of considering VNS in the differential diagnosis of soft-tissue masses, even in atypical locations. The present case report describes a 24-year-old male presenting with a decade-long history of pain and swelling in his right index finger. Despite initial radiographic findings being normal, Magnetic Resonance Imaging (MRI) revealed a well-defined soft-tissue mass involving the proximal and middle phalanx, flexor tendons and annular pulley. The presence of haemosiderin deposition within the mass was evident on MRI. The patient underwent open synovectomy, during which a brownish nodular synovium was observed, further supporting the diagnosis of VNS. Histopathological Examination (HPE) of the removed synovial tissue confirmed the presence of haemosiderin granules and haemosiderin-laden macrophages, solidifying the diagnosis of VNS. Post-surgery, the patient initiated a regimen of passive flexion and extension exercises for 15 days. At the 12-month follow-up, there were no clinical or radiological signs of recurrence and the patient had regained full range of motion.

Keywords

• rare disease
• surgical treatment
• synovectomy
• synovium