Eefting Daniël, Schrage Yvonne M, Geirnaerdt Maartje J A, Le Cessie Saskia, Taminiau Anthonie H M, Bovée Judith V M G, Hogendoorn Pancras C W
Department of Pathology, Orthopedic Surgery, Leiden University Medical Center, The Netherlands.
Am J Surg Pathol. 2009 Jan;33(1):50-7. doi: 10.1097/PAS.0b013e31817eec2b.
The distinction between benign and malignant cartilaginous tumors of bone is one of the most difficult subjects in surgical pathology. The grading of chondrosarcoma also seems to vary considerably among pathologists. However, clinical management differs. The purpose of this study was (1) to investigate interobserver variability in histological diagnosis and grading of central cartilaginous tumors and (2) to assess the diagnostic value of defined histologic parameters in differentiating enchondroma and central grade I chondrosarcoma. The interobserver variability was assessed using a set of 16 cases evaluated by 18 specialized pathologists. Subsequently, 20 enchondromas and 37 central grade I chondrosarcomas diagnosed in a multidisciplinary team with full clinical, radiologic, and pathologic data available with 10 years of follow-up were collected. Cytologic and tissue-architectural features were assessed to find an optimal set of parameters to differentiate enchondroma from central grade I chondrosarcoma. We demonstrate considerable variation in the histologic assessment of cartilaginous tumors (weighted kappa=0.78). The distinction between enchondroma and grade I chondrosarcoma was shown to be the most disconcordant (kappa coefficient=0.54), and also the differentiation between grade I and grade II chondrosarcoma was subjected to variation (kappa coefficient=0.80). The application of a combination of 5 parameters (high cellularity, presence of host bone entrapment, open chromatin, mucoid matrix quality, and age above 45 y) allowed optimal differentiation between enchondromas and central grade I chondrosarcomas. With a classification tree based on 2 parameters (mucoid matrix degeneration more than 20% and/or host bone entrapment present), 54 of the 57 (94.7%) cases were assessed correctly (sensitivity 95% and specificity 95%). Our study confirms the low reliability of the diagnosis and grading of central chondrosarcoma. However, these classifications guide therapeutic decision making in daily practice. Therefore, we propose a classification model that, combined with a tailored radiologic assessment, may improve reliability of the diagnosis of cartilaginous tumors.
骨软骨肿瘤良恶性的鉴别是外科病理学中最具挑战性的课题之一。软骨肉瘤的分级在病理学家之间似乎也存在很大差异。然而，临床处理方式有所不同。本研究的目的是：（1）调查中央型软骨肿瘤组织学诊断和分级中的观察者间变异性；（2）评估特定组织学参数在鉴别内生软骨瘤和中央型I级软骨肉瘤中的诊断价值。观察者间变异性通过18位专业病理学家对一组16例病例的评估来进行测定。随后，收集了多学科团队诊断的20例内生软骨瘤和37例中央型I级软骨肉瘤，这些病例具备完整的临床、放射学和病理学数据，并进行了10年的随访。评估了细胞学和组织结构特征，以找到一组区分内生软骨瘤和中央型I级软骨肉瘤的最佳参数。我们发现软骨肿瘤的组织学评估存在相当大的变异性（加权kappa=0.78）。内生软骨瘤和I级软骨肉瘤之间的鉴别差异最大（kappa系数=0.54），I级和II级软骨肉瘤之间的区分也存在变异性（kappa系数=0.80）。应用5个参数（高细胞密度、宿主骨包埋、开放染色质、黏液样基质质量和年龄大于45岁）的组合能够最佳地区分内生软骨瘤和中央型I级软骨肉瘤。基于2个参数（黏液样基质退变超过20%和/或存在宿主骨包埋）的分类树，57例病例中的54例（94.7%）被正确评估（敏感性95%，特异性95%）。我们的研究证实了中央型软骨肉瘤诊断和分级的可靠性较低。然而，这些分类在日常实践中指导治疗决策。因此，我们提出一种分类模型，结合针对性的放射学评估，可能会提高软骨肿瘤诊断的可靠性。
