Pathology of the temporomandibular joint of patients with rheumatoid arthritis - Case reports of secondary amyloidosis and macrophage populations

Introduction: The pathogenetic features of rheumatoid arthritis of the temporomandibular joint (TMJ) are not well defined. In this paper the histological features of TMJs affected by rheumatoid arthritis, and the detection of secondary amyloidosis and macrophage populations in the TMJs of two patients with progressive rheumatoid arthritis are described. Methods: In two patients (64-year-old man and 61-year-old woman) with rheumatoid arthritis total TMJ replacement were performed. The surgical specimens were studied histologically. Results: It was found that the articular cartilage had been completely replaced by proliferating fibrous tissue. Congo red staining and polarizing microscopy revealed amyloid deposition in the connective tissue of the joint space. Immunohistochemical staining showed CD 68 positive macrophages around the amyloid deposition in the proliferating soft tissue. Conclusion: TMJ involvement in rheumatoid arthritis followed the same destructive pathway as in other joints. Amyloid deposition and macrophage populations were detected in two TMJs affected by rheumatoid arthritis.