Tumor size is an important prognostic feature in many synoptic reports. The best format to report this feature is not clearly defined.
To define formatting features that impact the significance of tumor size.
We reviewed multiple formatting features of tumor size in synoptic reports and correlated them with size distribution, reproducibility, and other pathologic features.
Reporting tumors in millimeters rather than centimeters was more precise because of reduced rounding error and was significantly more reproducible (P = .01). Tumor sizes where the pathologist was concerned that the size may be underestimated are associated with significantly higher tumor N stage than tumors of similar size that are not so identified. Reported tumor sizes in multifocal tumors are also associated with significantly higher N stage than unifocal tumors of the same size.
Tumor sizes should be reported in millimeters, and when tumors are reported as either “at least” a specific size or as “multifocal” this information should also be recorded because these sizes likely underestimate the true biologic potential of the tumor.
The authors have no relevant financial interest in the products or companies described in this article.