The distinction of benign from malignant follicular thyroid neoplasms remains a difficult task in diagnostic fine-needle aspiration cytology, and some discrepant results have been reported for the individual immunocytochemical markers of malignancy proposed so far. The aim of this study was to test if the combined use of a panel of markers could improve the diagnostic accuracy in the preoperative cytological evaluation of ‘follicular neoplasms’ in an attempt to reduce the number of thyroidectomies performed for benign lesions. The immunocytochemical expression of galectin-3, HBME-1, thyroperoxidase, cytokeratin-19 and keratan-sulfate was retrospectively analyzed in 125 consecutive fine-needle aspiration samples (cell blocks) of indeterminate diagnoses of ‘follicular thyroid neoplasm’, and compared with their corresponding surgical specimens, including 33 follicular carcinomas, 42 papillary carcinomas and 50 follicular adenomas. Statistical analysis on each marker confirmed that galectin-3 and HBME-1 were the most sensitive (92% and 80% respectively) and specific (94% and 96% respectively) molecules. The use of these two markers sequentially in non-oncocytic lesions (testing HBME-1 as a second marker whenever galectin-3 proved negative) increased the sensitivity and specificity up to 97% and 95% respectively. In oncocytic lesions, HBME-1 proved to be less sensitive, and the sequential combination of galectin-3 and cytokeratin-19 reached 100% of both specificity and sensitivity. Our data showed that, as compared with the use of single markers, the sequential combination of two markers represents the most accurate immunohistochemical panel in managing patients with a fine-needle aspiration biopsy diagnosis of ‘follicular neoplasms’, especially in otherwise controversial categories such as oncocytic tumours. The combination of three or more markers did not substantially improve the diagnostic accuracy of the test.

Lung neuroendocrine tumors are catalogued in four categories by the World Health Organization (WHO 2004) classification. Its reproducibility and prognostic efficacy was disputed. The WHO 2010 classification of digestive neuroendocrine neoplasms is based on Ki67 proliferation assessment and proved prognostically effective. This study aims at comparing these two classifications and at defining a prognostic grading system for lung neuroendocrine tumors. The study included 399 patients who underwent surgery and with at least 1 year follow-up between 1989 and 2011. Data on 21 variables were collected, and performance of grading systems and their components was compared by Cox regression and multivariable analyses. All statistical tests were two-sided. At Cox analysis, WHO 2004 stratified patients into three major groups with statistically significant survival difference (typical carcinoid vs atypical carcinoid (AC), P=0.021; AC vs large-cell/small-cell lung neuroendocrine carcinomas, P<0.001). Optimal discrimination in three groups was observed by Ki67% (Ki67% cutoffs: G1 <4, G2 4–<25, G3 ≥25; G1 vs G2, P=0.021; and G2 vs G3, P≤0.001), mitotic count (G1 ≤2, G2 >2–47, G3 >47; G1 vs G2, P≤0.001; and G2 vs G3, P≤0.001), and presence of necrosis (G1 absent, G2 <10% of sample, G3 >10% of sample; G1 vs G2, P≤0.001; and G2 vs G3, P≤0.001) at uni and multivariable analyses. The combination of these three variables resulted in a simple and effective grading system. A three-tiers grading system based on Ki67 index, mitotic count, and necrosis with cutoffs specifically generated for lung neuroendocrine tumors is prognostically effective and accurate.

Adrenocortical carcinoma (ACC) is diagnosed using the histopathological Weiss score (WS), but remains clinically elusive unless it has metastasized or grows locally invasive. Previously, we proposed the objective IGF2 methylation score as diagnostic tool for ACC. This multicenter European cohort study validates these findings. Patient and tumor characteristics were obtained from adrenocortical tumor patients. DNA was isolated from frozen specimens, where after DMR2, CTCF3, and H19 were pyrosequenced. The predictive value of the methylation score for malignancy, defined by the WS or metastasis development, was assessed using receiver operating characteristic curves and logistic and Cox regression analyses. Seventy-six ACC patients and 118 patients with adrenocortical adenomas were included from seven centers. The methylation score and tumor size were independently associated with the pathological ACC diagnosis (OR 3.756 95% CI 2.224–6.343; OR 1.467 95% CI 1.202–1.792, respectively; Hosmer–Lemeshow test P = 0.903), with an area under the curve (AUC) of 0.957 (95% CI 0.930–0.984). The methylation score alone resulted in an AUC of 0.910 (95% CI 0.866–0.952). Cox regression analysis revealed that the methylation score, WS and tumor size predicted development of metastases in univariate analysis. In multivariate analysis, only the WS predicted development of metastasis (OR 1.682 95% CI 1.285–2.202; P < 0.001). In conclusion, we validated the high diagnostic accuracy of the IGF2 methylation score for diagnosing ACC in a multicenter European cohort study. Considering the known limitations of the WS, the objective IGF2 methylation score could potentially provide extra guidance on decisions on postoperative strategies in adrenocortical tumor patients.