Pancreatic neuroendocrine tumors≤2 cm are increasingly common, and the most significant predictors of disease-specific survival are grade and race. The SEER database excludes PNETs considered to be benign, and rates of extrapancreatic extension, nodal metastasis, and distant metastasis are overestimated. Small size, however, does not preclude malignant behavior.

IMPORTANCE Approximately 20% of thyroid nodules display indeterminate cytology. Molecular testing can refine the risk of malignancy and reduce the need for diagnostic hemithyroidectomy.OBJECTIVE To compare the diagnostic performance between an RNA test (Afirma genomic sequencing classifier) and DNA-RNA test (ThyroSeq v3 multigene genomic classifier). DESIGN, SETTING, AND PARTICIPANTSThis parallel randomized clinical trial of monthly block randomization included patients in the UCLA Health system who underwent thyroid biopsy from August 2017 to January 2020 with indeterminate cytology (Bethesda System for Reporting Thyroid Cytopathology category III or IV). INTERVENTIONS Molecular testing with the RNA test or DNA-RNA test. MAIN OUTCOMES AND MEASURES Diagnostic test performance of the RNA test compared with the DNA-RNA test. The secondary outcome was comparison of test performance with prior versions of the molecular tests. RESULTS Of 2368 patients, 397 were eligible for inclusion based on indeterminate cytology, and 346 (median [interquartile range] age, 55 [44-67] years; 266 [76.9%] women) were randomized to 1 of the 2 tests. In the total cohort assessed for eligibility, 3140 thyroid nodules were assessed, and 427 (13.6%) nodules were cytologically indeterminate. The prevalence of malignancy was 20% among indeterminate nodules. The benign call rate was 53% (95% CI, 47%-61%) for the RNA test and 61% (95% CI, 53%-68%) for the DNA-RNA test. The specificities of the RNA test and DNA-RNA test were 80% (95% CI, 72%-86%) and 85% (95% CI, 77%-91%), respectively (P = .33); the positive predictive values (PPV) of the RNA test and DNA-RNA test were 53% (95% CI, 40%-67%) and 63% (95% CI, 48%-77%), respectively (P = .33). The RNA test exhibited a higher PPV compared with the prior test version (Afirma gene expression classifier) (54% [95% CI, 40%-67%] vs 38% [95% CI, 27%-48%]; P = .01). The DNA-RNA test had no statistically significant difference in PPV compared with its prior version (ThyroSeq v2 next-generation sequencing) (63% [95% CI, 48%-77%] vs 58% [95% CI, 43%-73%]; P = .75). Diagnostic thyroidectomy was avoided in 87 (51%) patients tested with the RNA test and 83 (49%) patients tested with the DNA-RNA test. Surveillance ultrasonography was available for 90 nodules, of which 85 (94%) remained stable over a median of 12 months follow-up.CONCLUSIONS AND RELEVANCE Both the RNA test and DNA-RNA test displayed high specificity and allowed 49% of patients with indeterminate nodules to avoid diagnostic surgery. Although previous trials demonstrated that the prior version of the DNA-RNA test was more specific than the prior version of the RNA test, the current molecular test techniques have no statistically significant difference in performance.

BRAF and KRAS mutations in ovarian serous borderline tumors (OSBTs) and ovarian low-grade serous carcinomas (LGSCs) have been previously described. However, whether those OSBTs would progress to LGSCs or those LGSCs were developed from OSBT precursors in previous studies is unknown. Therefore, we assessed KRAS and BRAF mutations in tumor samples from 23 recurrent LGSC patients with known initial diagnosis of OSBT. Paraffin blocks from both OSBT and LGSC samples were available for 5 patients, and either OSBT or LGSC were available for another 18 patients. Tumor cells from paraffin-embedded tissues were dissected out for mutation analysis by conventional polymerase chain reaction (PCR) and Sanger sequencing. Tumors that appeared to have wild-type KRAS by conventional PCR–Sanger sequencing were further analyzed by full COLD (coamplification at lower denaturation temperature)-PCR and deep sequencing. Full COLD-PCR was able to enrich the amplification of mutated alleles. Deep sequencing was performed with the Ion Torrent personal genome machine (PGM). By conventional PCR–Sanger sequencing, BRAF mutation was detected only in one patient and KRAS mutations were detected in 10 patients. Full COLD-PCR deep sequencing detected low-abundance KRAS mutations in eight additional patients. Three of the five patients with both OSBT and LGSC samples available had the same KRAS mutations detected in both OSBT and LGSC samples. The remaining two patients had only KRAS mutations detected in their LGSC samples. For patients with either OSBT or LGSC samples available, KRAS mutations were detected in 7 OSBT samples and 6 LGSC samples. To our surprise, patients with the KRAS G12V mutation appeared to have shorter survival times. In summary, KRAS mutations are very common in recurrent LGSC, while BRAF mutations are rare. The findings indicate that recurrent LGSC can arise from proliferation of OSBT tumor cells with or without detectable KRAS mutations.

Lymph node dissection may decrease recurrence leading to reoperation for patients with MTC. Reoperation is a viable strategy to achieve long-term disease-free survival in appropriately selected patients. Central neck dissection remains underused.

Background: Tall cell variant (TCV) and diffuse sclerosing variant (DSV) of papillary thyroid cancer are aggressive subtypes, for which tumors £ 1 cm have not been exclusively studied. Methods: The SEER database ) was used to compare characteristics of TCV £ 1 cm (mTCV) and DSV £ 1 cm (mDSV) with classic papillary thyroid microcarcinoma (mPTC). Survival was analyzed with the KaplanMeier method and log-rank test, and risk factors for nodal metastases with chi-square analysis and binary logistic regression. Results: There were 97 mTCV, 90 mDSV, and 18,260 mPTC patients. mTCV incidence increased by 79.9% ( p = 0.153) over the study period, while mDSV incidence decreased by 10.3% ( p = 0.315). Compared to classic mPTC, mTCV tended to be larger on average (7.1 mm vs. 5.3 mm, p < 0.001), with higher rates of multifocality (47.2% vs. 34.0% respectively, p = 0.018) and lymph-node examination (63.9% vs. 39.2% respectively, p < 0.001), while in mDSV, nodal metastases were more frequent (57.1% vs. 33.1% respectively, p = 0.007). Both aggressive variants had higher rates of extrathyroidal extension (27.8% mTCV vs. 13.3% mDSV vs. 6.1% mPTC, p < 0.001). Aggressive variants also received radioactive iodine more frequently (39.2% mTCV vs. 40.0% mDSV vs. 29.1% mPTC, p < 0.001). However, they were not statistically more likely to receive thyroidectomy over lobectomy compared to classic mPTC. There were no significant differences in overall and disease-specific survival between the histologies. In mTCV, after adjustment, extrathyroidal extension was independently associated with size > 7 mm (odds ratio (OR) 4.4 [CI 1.5-13.6]) and nodal metastasis with multifocality ) and extrathyroidal extension . No statistically significant predictors of extrathyroidal extension or nodal metastasis in mDSV were observed. Conclusions: Aggressive variants of mPTC tend to exhibit more aggressive pathologic characteristics than classic mPTC, but survival appears to be similar. Treatment with total thyroidectomy and central lymphadenectomy may be warranted if the diagnosis can be made pre-or intraoperatively.