Mismatch Between Preoperative MRI Findings and Postoperative Histological Results in the Treatment of Tenosynovial Giant Cell Tumor

BACKGROUND/AIM: Tenosynovial giant cell tumor (TGCT) is a rare disease of young adults with a high number of cases going unreported. Despite an international consensus meeting of experts in June 2022, the majority of such patients repeatedly pose problems, even for experienced clinicians. This study deals with the question of how often postoperative histopathological findings are consistent with preoperative magnetic resonance imaging (MRI) findings.

PATIENTS AND METHODS: In a retrospective data analysis, we investigated 137 patients at our department who had undergone synovectomy between 1991 and 2019.

INCLUSION CRITERIA: positive MRI findings with evidence of T1- and T2-weighted sequence low-signal representation of the TGCT with inhomogeneous contrast medium uptake because of hemosiderin, subsequent synovectomy and complete histological report showing inconsistency with MRI findings. Because of the heterogeneity of the study group, we can only report descriptive statistics.

RESULTS: The average age at diagnosis was 38 (range=9-73) years. Of 137 cases, 52 with complete data sets were included in the study. In 37 (71%) out of these 52 patients, MRI and histological findings were consistent. Of the 52 patients, 15 (29%) had a false-positive MRI finding for TGCT.

CONCLUSION: Although imaging showed pathognomonic characteristics, the diagnosis of TGCT was not confirmed histopathologically in almost 29%. We therefore recommend a preoperative biopsy, especially in case of doubt, and treatment of TGCT in designated centers.