Murphy William M, Takezawa Kimiko, Maruniak Nicholas A
Department of Pathology, University of Florida College of Medicine, Gainsville, Florida, USA.
J Urol. 2002 Sep;168(3):968-72. doi: 10.1016/S0022-5347(05)64553-3.
Morphological classifications designed by experts to stratify neoplasms according to biological potential must define categories that are reproducible among practitioners or the schemes actually create the heterogeneous populations that they seek to avoid. The application of the 1998 World Health Organization/International Society of Urologic Pathology scheme for urothelial neoplasms was studied in a community practice setting. We documented interpretive discrepancies for each category of neoplasm and determined whether a period of pathologist education may have a positive effect on the frequency of discrepant interpretations. The results suggest that patients may benefit from modifying the classification system.
A consecutive series of specimens was divided into learning and study sets that were each independently examined by 3 pathologists. Specimens in the learning set were interpreted without previous structured education, while those in the study set were interpreted immediately after intensive education. Interpretations for each specimen were compared and interpretive discrepancies were analyzed.
Case distribution after education was similar among the pathologists but interpretations for any particular specimen often differed. The level of interpretive discrepancies varied according to the morphological similarity among categories in the classification scheme and was not necessarily decreased by education. When pathologists were required to discriminate between papillary urothelial neoplasm of low malignant potential and low grade carcinoma, the discrepancies were 50% after education compared with 39% before education. In contrast, there were no discrepancies when the discrimination was between papillary urothelial neoplasm of low malignant potential and high grade carcinoma or carcinoma in situ. Eliminating categories with poor reproducibility markedly improved the likelihood of unanimous agreement among practitioners but a probably irreducible level of 10% discrepancies remained.
The 1998 World Health Organization/International Society of Urologic Pathology classification of urothelial neoplasms requires certain discriminations that cannot be reliably made by practitioners. Modifying the scheme to create categories of low grade neoplasm and high grade carcinoma would markedly increase its practical value to patients without significantly altering patient care.
由专家设计的根据生物学潜能对肿瘤进行分层的形态学分类，必须定义出在从业者之间可重复的类别，否则该方案实际上会产生它试图避免的异质性群体。我们在社区实践环境中研究了1998年世界卫生组织/国际泌尿病理学会的尿路上皮肿瘤分类方案的应用。我们记录了每种肿瘤类别的解释差异，并确定病理学家的教育阶段是否可能对差异解释的频率产生积极影响。结果表明，修改分类系统可能会使患者受益。
将一系列连续的标本分为学习组和研究组，每组由3名病理学家独立检查。学习组的标本在没有先前结构化教育的情况下进行解释，而研究组的标本在强化教育后立即进行解释。比较每个标本的解释并分析解释差异。
教育后病理学家之间的病例分布相似，但对任何特定标本的解释往往不同。解释差异的程度根据分类方案中类别之间的形态学相似性而有所不同，并且不一定因教育而降低。当要求病理学家区分低恶性潜能的乳头状尿路上皮肿瘤和低级别癌时，教育后的差异为50%，而教育前为39%。相比之下，当区分低恶性潜能的乳头状尿路上皮肿瘤与高级别癌或原位癌时，没有差异。消除可重复性差的类别显著提高了从业者之间达成一致意见的可能性，但仍有10%的差异可能无法消除。
1998年世界卫生组织/国际泌尿病理学会的尿路上皮肿瘤分类需要进行某些从业者无法可靠做出的区分。修改该方案以创建低级别肿瘤和高级别癌的类别，将显著增加其对患者的实用价值，而不会显著改变患者护理。
