CAP TODAY Pathology/Laboratory Medicine/Laboratory Management
Correspondence: Dr. Jacob R. Bledsoe at jacob.bledsoe@umassmemorial.org
Impact of a genomic classifier on indeterminate thyroid nodules
Twenty to 25 percent of thyroid nodules examined are classified as indeterminate thyroid cytology, and the associated risk of malignancy ranges from five to 30 percent. The genomic classifier ThyroSeq, a targeted next-generation sequencing technology, could classify indeterminate thyroid cytology (ITC) nodules as malignant and nonmalignant. The authors characterized their institutional experience with ThyroSeq testing. They retrospectively identified all patients seen from January 2015 through November 2019 who had ITC nodules analyzed with ThyroSeq. The authors reviewed relevant clinical, pathologic, and resection data. For the 133 patients identified, the diagnostic categories included atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS; n = 65; 48.9 percent), suspicious for follicular neoplasm (SFN; n = 48; 36.1 percent), and suspicious for Hürthle cell neoplasm (n = 20; 15 percent). More than half of the cases of papillary thyroid carcinoma (56.3 percent) and more than one-third of the cases of noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP; 37.5 percent) were classified as SFN. Most patients (n = 87; 65.4 percent) did not undergo resection. Of these, 73 (83.9 percent) were negative for all molecular alterations. Of the 54 cases with molecular alterations, isolated RAS or RAS-like variants were most common (n = 35; 64.8 percent), and nine of the variants (25.7 percent) were identified in papillary thyroid carcinoma and eight (22.9 percent) in NIFTP. NRAS was the most common molecular alteration (n = 20; 37 percent), followed by HRAS (n = 6; 11.1 percent), which was primarily detected in NIFTP cases (n = 4 of 6; 66.7 percent). The authors concluded that resection was avoided in 73 patients (54.9 percent) because of negative ThyroSeq results. ThyroSeq v2 and v3 provided a more accurate categorization of ITC nodules, improved patient management, and a reduction in unnecessary surgical procedures.
Abdelhakam DA, Mojica RE, Huenerberg KA, et al. Impact of a genomic classifier on indeterminate thyroid nodules: an institutional experience. J Am Soc Cytopathol. 2021;10(2):155–163.
Correspondence: Dr. Aziza Nassar, Department of Laboratory Medicine and Pathology, Mayo Clinic, 4500 San Pablo Rd., Jacksonville, FL 32224
Variability in synoptic reporting of colorectal cancer pT4a category and lymphovascular invasion
Serosal involvement (pT4a category) and lymphovascular invasion have prognostic significance in colorectal carcinoma, but their assessment is subject to interobserver variation. The authors provided a large-scale assessment of interobserver variability in pT4a category and lymphovascular invasion reporting in real-world practice and explored the impact of information from guidelines addressing variability in reporting these features. They analyzed 1,555 consecutive synoptic reports of colorectal carcinoma using multivariate logistic regression. Interobserver variability before and after presenting guideline information was assessed using an image-based survey. Significant differences in the odds of reporting pT4a versus pT3 category, detecting lymphovascular invasion of any type, and detecting large-vessel invasion were identified among hospital sites and for individual pathologists when compared with the median for pathologists at the same site. Consistent with these results, interobserver agreement regarding T4a staging and lymphovascular invasion was only moderate (all κ ≤ 0.57) in the image-based survey. The provision of information from guidelines did not tend to increase interobserver agreement in the survey, although responses in favor of using an elastic stain increased following recommendations supporting their use. However, when observers were provided with elastic-stained images, interobserver agreement remained only moderate (κ = 0.55). The authors concluded that real-world reporting of pT4a category and lymphovascular invasion shows substantial variability at local and regional levels. This study underscores the need to address features of prognostic significance in quality initiatives and offers a novel method through which synoptic data can be harnessed to monitor reporting patterns and provide individualized feedback.
Naso JR, Yang HM, Schaeffer DF. Variability in synoptic reporting of colorectal cancer pT4a category and lymphovascular invasion. Arch Pathol Lab Med. 2021;145(3):343–351. doi:10.5858/arpa.2020-0124-OA
Correspondence: Dr. David F. Schaeffer at david.schaeffer@vch.ca