The role of magnetic resonance imaging in the differential diagnosis of pigmented villonodular synovitis (tenosynovial giant cell tumor) and some other knee joint synovitis

Summary. Often, patients seek medical attention at specialized institutions with a preliminary diagnosis of «synovitis of the knee joint». Diagnosis and differential diagnosis begin with a clinical examination, continue with evaluation of various non-invasive instrumental research methods, visual evaluation intraoperatively, and end only with a pathohistological evaluation of the biological material obtained. Pigmented villonodular synovitis (PVNS) (also found in the literature as a tenosynovial giant cell tumor) is a rare disease that has no pathognomonic symptoms, and therefore has difficulty in diagnosis. This paper examines the role and features of magnetic resonance imaging (MRI) in the diffe­rential diagnosis of the PVNS (tenosynovial giant cell tumor) of the knee joint with other knee joint synovitis. The purpose of this study was to study and analyze the possibilities and role of MRI for differential diagnosis of PVNS (tenosynovial giant cell tumor) of the knee joint with other knee joints (invasive and invasive). Materials and methods. The study is based on the ana­lysis of the treatment of 52 patients with a pathohistologically verified diagnosis of PVNS (tenosynovial giant cell tumor) of the knee joint (group 1), 24 patients with primary (idiopathic) synovial chondromatosis of the knee (group 2), 76 patients with rheumatoid arthritis with knee joint synovitis (group 3) and 33 patients with chronic synovitis of the knee joint (group 4), who were treated between 2010 and 2019 at the State Institution «Institute of Traumatology and Orthopedics of the National Academy of Medical Sciences of Ukraine», Kyiv. Results and discussion. By analyzing the MRI of 185 patients with knee synovitis, it can be concluded that the accuracy, sensitivity and specificity of MRI data are higher in patients with PVNS and synovial chondromatosis than in patients with chronic synovitis and rheumatoid arthritis. Conclusion. Having high rates of sensitivity (91%), specificity (79%) and accuracy (87%), the MRI method is quite effective and plays a leading role both in the diagnosis of PVNS of the knee joint before surgery and in monitoring the quality of treatment in the postoperative period.