Synovial chondromatosis of the temporomandibular joint with immunohistochemical findings: report of a case

[Expression of cartilage oligomeric matrix protein in the synovial chondromatosis of the temporomandibular joint]

OBJECTIVE

To detect the expression of cartilage oligomeric matrix protein (COMP) in the synovial chondromatosis of the temporomandibular joint (TMJSC), and to discuss the possible interactions between COMP, transforming growth factor (TGF)-β3, TGF-β1 and bone morphogenetic protein-2 (BMP-2) in the development of this neoplastic disease.

METHODS

Patients in Peking University School and Hospital of Stomatology from January 2011 to February 2020 were selected, who had complete medical records, TMJSC was verified histologically after operation. The expressions of COMP, TGF-β3, TGF-β1 and BMP-2 in the TMJSC of the temporomandibular joint were detected by immunohistochemistry and quantitative real-time PCR (RT-PCR) at the protein level and mRNA level respectively, compared with the normal synovial tissue of temporomandibular joint. The histological morphology, protein expression and distribution of TMJSC tissues were observed microscopically, and the positive staining proteins were counted and scored. SPSS 22.0 statistical software was used to analyze the expression differences between the related proteins in TMJSC tissue and the normal synovial tissue of temporomandibular joint and to compare their differences. P < 0.05 indicated that the difference was statistically significant.

RESULTS

Immunohistochemical results showed that the positive expression of COMP in TMJSC tissues was mostly found in synovial tissues and chondrocytes adjacent to synovial tissues, and the difference was statistically significant, compared with the normal temporomandibular joint synovial tissues. The positive expression of COMP was significantly different between recurrent TMJSC and non-recurrent ones. The positive expressions of TGF-β3, TGF-β1 and BMP-2 were higher than the normal synovial tissue, and were also mostly found in the synovial cells and adjacent chondrocytes, which was further confirmed by Western blot. According to the RT-PCR results, the expressions of COMP, TGF-β3, TGF-β1 and BMP-2 in TMJSC were higher than those in the normal synovial tissue.

CONCLUSION

The expression of COMP in TMJSC of temporomandibular joint increased significantly, compared with the normal synovial tissue. There may be interactions between COMP and cytokines related to the proliferation and differentiation, like TGF-β3, TGF-β1 and BMP-2, which may play a potential role in the pathogenesis of TMJSC.

Synovial chondromatosis of the temporomandibular joint: clinical, diagnostic, and histomorphologic findings

Objective. The primary diagnosis of synovial chondromatosis of the temporomandibular joint is extremely rare. Often many months, or even years pass before the diagnosis is confirmed. Study Design. Eight patients with synovial chondromatosis were treated by arthrotomy. In addition to the definitive diagnosis, histologic classification according to the stages proposed by Milgram was undertaken and confirmed with the literature. Results. The predominant symptoms of synovial chondromatosis, including pain, swelling, restricted movement of the mandible, and crepitation, were evaluated. Nevertheless, more than 80% of the patients were previously primarily treated on the basis of other tentative diagnoses. Conclusion. Synovial chondromatosis of the temporomandibular joint should be included in the differential diagnosis of chronic swelling and pain in the preauricular region, and the patient should be sent for appropriate diagnostics and therapy at an early stage.

Condylar hyperplasia associated to synovial chondromatosis of the temporomandibular joint: a case report

Condylar hyperplasia is a slowly developing malformation of the mandible, with elongation of the mandibular neck, that generally results in facial asymmetry. Synovial chondromatosis is a benign chronic disorder characterized by the formation of multiple small nodules of hyaline cartilage as a result of metaplasia of the synovial connective tissue. It affects mostly the large joints, particularly the knee, hip, elbow and ankle. The temporomandibular joint (TMJ) is rarely affected. The case of a 42-year-old male with a history of left preauricular pain and swelling and deviation of the mandible to the left upon opening the mouth is presented. Computed tomography disclosed hyperplasia of the left condyle with loose radiopaque bodies within the joint cavity. The left TMJ was subject to open surgery, which included resection of four loose bodies and a remodeling condylectomy. The histopathological study confirmed the diagnosis of condylar hyperplasia and chondromatosis of the left TMJ.

[Synovial chondromatosis (chondrometaplasia). Contribution to the differential diagnosis of temporomandibular joint diseases]

A rare case of synovial chondromatosis of the temporomandibular joint with unspecific symptoms is presented. This causes difficulties in classifying the different clinically and technically acquired features at differential diagnosis. The concept of chondrometaplasia as being triphasic and self-limiting is strongly supported and extreme care should be taken during therapy in order to avoid any unnecessary destruction and mutilation. This case seems to indicate that chronic parafunctional overload was the initiating stimulus for this reactive metaplastic process. Nonphysiologic overstrain of any cause should be diagnosed and corrected.