The thyroid fine-needle aspiration (FNA) diagnosis of Hü rthlecell neoplasm (HCN)/follicular neoplasm with oncocytic features (FNOF) does not differentiate between

Context.— Pancreatic cystic lesions (PCLs) are very common, and their detection is increasing with the advances in imaging techniques. Because of the major implications for management, distinguishing between neoplastic and nonneoplastic PCLs is critical. Neoplastic cysts with potential to progress into cancer include mucinous PCLs (intraductal papillary mucinous neoplasms and mucinous cystic neoplasms) and nonmucinous cysts (solid pseudopapillary tumors, serous cystic neoplasms, and neuroendocrine tumors with cystic degeneration). Nonneoplastic cysts with no risk of malignant transformation include pseudocysts, retention cysts, lymphoepithelial cysts, cystic pancreatic lymphangioma, and duplication cyst/ciliated foregut cysts. The role of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) cytology with cyst fluid analysis in the diagnosis of PCLs has evolved during the last decade; however, a definitive diagnosis on cytologic specimens is hampered by the sparse cellularity and can be challenging. EUS-FNA can play an important role to differentiate low-risk from high-risk pancreatic cysts and to distinguish between patients with cysts who need clinical follow-up versus those who require surgery. Objective.— To provide an integrative approach to diagnose pancreatic cystic lesions using EUS-FNA cytology and cyst fluid analysis, along with clinical, radiologic, histologic, genetic, and molecular characteristics. Data Sources.— The review and analysis of the latest literature describing pancreatic cystic lesions. Conclusions.— Accurate diagnosis of PCLs requires a multidisciplinary and multimodal team approach, including the integration of clinical findings, imaging, cytology, cyst fluid analysis, and molecular testing.

BACKGROUND:The solid variant of papillary thyroid carcinoma (SVPTC) comprises approximately 3% of thyroid cancers, and there are conflicting reports about its behavior in the literature. The cytology of SVPTC is limited to 3 single case reports, a review article, and a monograph. We present the first cytologic study of SVPTC. METHODS: Fine-needle aspiration smears obtained with ultrasound guidance from 13 patients with histologically pure SVPTC were reviewed, and the cytologic features recorded. Ultrasound images were retrieved from radiology and were correlated with low-power histology images. Intratumor vascularity on Doppler imaging was correlated with cellularity in cytology samples. RESULTS:Three cytomorphologic patterns of SVPTC were identified: cohesive, syncytial-type tissue fragments; microfollicles/trabeculae; and dyshesive single cells. All 3 SVPTCs in the first group were encapsulated without invasion. Two of 6 SVPTCs in the second group had a single lymph node metastasis; 4 were encapsulated, and 2 had pushing borders. Ultrasound images in the first and second SVPTC groups were similar, with the majority revealing a well defined, solid nodule with minimal intranodular vascularity. All 4 SVPTCs in the third group had infiltrative borders; and, with the exception of one 0.8-cm tumor, all had multiple lymph node metastases. Ultrasound in the third group revealed irregular borders. RET/PTC1 and RET/PTC3