Synovial chondrosarcoma: a single-institution experience with molecular investigations and review of the literature

Pathology of intra-articular tumours and tumour-like lesions: pearls, pitfalls and rarities from a general surgical pathology practice

Intra-articular tumours are uncommonly encountered in routine practice and may present diagnostic challenges to pathologists. Challenges unique to this site include distinction from more common reactive synovial conditions, which are far more common; histologic variability; superimposed reactive changes; and often, lack of provided clinicoradiological context. This article reviews the pathology of the synovial tumours and tumour-like lesions, including diagnostic pearls, pitfalls and rare entities.

Primäre synoviale Chondromatose

Hintergrund

Die primäre synoviale Chondromatose (SC) ist eine seltene Erkrankung der Synovialmembran unklarer Ätiologie. Der aktuelle Wissensstand zu dieser Erkrankung soll in einer kurzen Übersicht dargestellt werden.

Methoden

Übersichtsarbeiten und rezente Fallberichte zur SC wurden systematisch ausgewertet und mit Daten eigener Fälle in Kontext gesetzt.

Ergebnisse

Auf Grund neuer genomischer Daten wird die SC als benigne Neoplasie eingestuft. In 60 % der Fälle liegen Mutationen im Fibronektin-1-Gen (FN1) und/oder im Gen für den Activin-A-Typ-II-Rezeptor (ACVR2A) vor. Diagnoseweisend ist die Magnetresonanztomographie (MRT) und die meist arthroskopische Biopsie der Synovia. An einem Fallbeispiel soll gezeigt werden, dass die Knorpelaggregate der SC radiologisch nicht immer schattengebend sein müssen. Differenzialdiagnostisch kommen Monarthritiden anderer Ursachen, andere Gelenk- und Muskelerkrankungen mit Mineralisierung sowie weitere von der Synovialmembran ausgehende Erkrankungen in Betracht. Die Entartungsrate liegt bei 2–4 %. Therapeutisch hat sich in den letzten Jahren das arthroskopische Vorgehen durchgesetzt, das an die Ausdehnung der Erkrankung adaptiert wird.

Schlussfolgerung

Genomische Untersuchungen sowie Fallserien und Fallberichte aus jüngerer Zeit werfen ein neues Licht auf die SC. Therapeutisch wird in jüngeren Arbeiten überwiegend arthroskopisch vorgegangen.

Intra-Articular Tumors

The intra-articular space is a relatively rare site of occurrence of neoplastic diseases. The 2 distinct groups of clinicopathologic entities that exhibit an almost exclusive tropism for the joints are represented by synovial chondromatosis and tenosynovial giant cell tumors (TGCT). Synovial chondromatosis is a locally aggressive chondrogenic neoplasm that very rarely can show malignant behavior. TGCT occur in 2 main variants, the localized variant and the more locally aggressive diffuse type. Malignant TCGT is exceedingly rare and is characterized by significant rates of both local recurrence and metastatic spread.

Prognostic importance of IDH mutations in chondrosarcoma: An individual patient data meta-analysis

Introduction

IDH1/2 mutations are prevalent in cartilaginous tumors including chondrosarcoma. This meta‐analysis using individual patient data (IPD) aimed to investigate the clinical and prognostic association of these mutations in chondrosarcoma patients.

Methods

Two electronic databases including PubMed and Web of Science were searched for relevant data. We included studies providing IPD of chondrosarcoma with available IDH1/2 mutational status for meta‐analysis. Chi‐square and t‐test were performed to compare the groups with and without IDH1/2 mutations. For survival analysis, log‐rank test, and Cox proportional hazards model were used to investigate the association of IDH mutations with patient outcomes.

Results

Fourteen studies with 488 patients were analyzed. IDH1 and IDH2 mutations were detected in 38.7% and 12.1% of cases, respectively. IDH1/2 mutations were significantly associated with an older age (p = 0.003), tumor origins (p < 0.001), tumor grades (p < 0.001), larger diameter (p = 0.003), relapse (p = 0.014), and patient mortality (p = 0.04). Multivariate Cox regression analysis adjusted for age, gender, tumor grade, and tumor sites confirmed the negative impact of IDH1/2 mutations on patient overall survival (HR = 1.90; 95% CI = 1.06–3.42; p = 0.03).

Conclusion

Our meta‐analysis demonstrated the distinct characteristics of IDH1/2‐mutated chondrosarcomas in comparison to those without mutations. These mutations could serve as an independent prognostic biomarker to better prognosticate patient outcomes and design appropriate treatment plans.

Chondrosarcoma of the Temporomandibular Joint: Systematic Review and Survival Analysis of Cases Reported to Date

The purpose of this systematic review was to summarize the available data on TMJ chondrosarcomas and to perform a survival analysis of cases reported to date. This review was conducted in accordance with the PRISMA. Two authors performed an electronic search of case reports of TMJ chondrosarcoma published until August 02, 2020. Forty-seven studies reporting 53 cases were included. Chondrosarcomas of the TMJ were more prevalent in women, with a male:female ratio of 1:1.4. Survival curves were significantly associated with histological diagnosis (p = 0.004), reconstructive surgery (p = 0.024), recurrence (p < 0.001), and distant metastasis (p = 0.001). Only distant metastasis was independently associated with survival (p = 0.017). TMJ chondrosarcomas presented with low recurrence and higher survival rates than other chondrosarcomas. Synovial subtype, absence of reconstructive surgery, and presence of local recurrence or distant metastasis were associated with poorer prognosis.