No abstract

Objective: To evaluate the effectiveness of the Bethesda System for Reporting Thyroid Cytopathology (BSRTC) and to analyze the causes of unclear diagnoses following BSRTC adoption. Study Design: According to the BSRTC, we reclassified cytologic samples originally diagnosed as ‘indeterminate’ with sequential surgical resection. Then, we analyzed the causes of cases, which were recategorized as ‘atypia undetermined significance/follicular lesion of undetermined significance (AUS/FLUS)’. Results: According to the BSRTC, 154 ‘indeterminate’ cases were reclassified as follows: unsatisfactory, n = 5 (3.2%); benign, n = 43 (27.9%); AUS/FLUS, n = 77 (50.0%); suspicious for a follicular neoplasm, n = 7 (7.1%); suspicious for a Hürthle cell neoplasm, n = 4 (2.6%); suspicious for malignancy, n = 15 (9.7%), and malignancy, n = 3 (1.9%). Then, the AUS/FLUS group was analyzed according to the scenarios proposed by the BSRTC. Fifty-nine (58.9%) cases of AUS/FLUS were due to suboptimal preparation. In addition, papillary microcarcinoma and coexisting Hashimoto’s thyroiditis caused inconclusive diagnoses. Conclusion: The BSRTC can be easily applied to thyroid fine-needle aspiration. We were able to reclassify indeterminate thyroid nodules into more detailed categories and thus reduce the number of cases classified as indeterminate. However, suboptimal preparation, papillary microcarcinoma, and coexisting Hashimoto’s thyroiditis precluded cytopathologists from making definitive diagnoses.

Lung cancer rarely occurs in young patients. Recent studies have demonstrated that epidemiologic data are closely correlated to some molecular characteristics. We investigated the clinicopathologic characteristics of lung adenocarcinoma in young patients and evaluated immunohistochemically detected epidermal growth factor receptor (EGFR) mutation status and anaplastic lymphoma kinase (ALK) positivity. Among lung adenocarcinoma patients, 31 cases were of the ≤ 40 yr-old group and 261 cases of > 50 yr-old group. Young patients were more likely to be females (67.7% vs 40.2%), and nonsmokers (58.1% vs 45.2%) and more often had high TNM stage (stage IV was 80.6% vs 52.1%) and had a high rate of distant metastasis (51.6% vs 28.0%) compared with older patients. The signet ring cell feature was more common (25.8% vs 11.5%) and lepidic growth pattern was rarely present (3.2% vs 16.5%) in the adenocarcinoma of young patients. There was no significant survival difference between the two age groups. The rate of EGFR mutation status and ALK positivity did not show a statistical difference between two groups. In conclusion, lung adenocarcinoma of young patients demonstrates distinct pathologic features with frequent presence of a signet ring cell feature and rare occurrence of lepidic growth pattern. Further investigation for other genetic abnormalities would be needed.