Appendiceal mucinous neoplasms constitute a diagnostic spectrum ranging from adenoma to mucinous adenocarcinoma. To date, many classification systems have been proposed to reflect the histomorphological diversity of neoplasms in this range and their clinical correspondence, and also to form a common terminology between the pathologist and clinicians. The aim of this review is to provide an updated perspective on the pathological features of appendiceal mucinous neoplasms. Using the 2016 Modified Delphi Consensus Protocol (Delphi) and the Eighth Edition of the American Joint Committee on Cancer (AJCC) Cancer Staging Manual, 19 cases presented from June 2011 to December 2016 were evaluated and diagnosed with appendiceal mucinous neoplasia. According to the Delphi, non-carcinoid epithelial tumours of the appendix were categorized in eight histomorphological architectural groups. These groups are adenoma, serrated polyp, low-grade appendiceal mucinous neoplasm, high-grade appendiceal mucinous neoplasm, mucinous adenocarcinoma, poorly-differentiated adenocarcinoma with signet-ring, signet-ring cell carcinoma and adenocarcinoma. The most common symptom was right lower quadrant pain. The median age of these cases was 60±15 years. There was a preponderance of females (F/M: 15/4). In our re-evaluation, six cases were diagnosed as serrated polyp. There were 11 cases in the LAMN group and two cases in the mucinous adenocarcinoma group. Using the Delphi and the AJCC manual, there were many changes in the classification, evaluation and treatment of appendiceal mucinous neoplasms. These classification systems have facilitated the compatibility and communication of clinicians and pathologists and have guided clinicians on treatment methods. Cite this article as: Gündoğar Ö, Kımıloğlu E, Komut N, et al. Evaluation of appendiceal mucinous neoplasms with a new classification system and literature review. Turk J Gastroenterol 2018; 29: 532-42.

Background/Objectives: Bladder cancer, predominantly urothelial carcinoma, is an important malignancy of the urinary system. Despite the same histologic grade and stage, some patients seem to have a worse prognosis. In this context, the epithelial–mesenchymal transition (EMT), characterized by the loss of E-cadherin and gain of vimentin expression, is an important process in tumor progression. Galectin-3, a lactose-binding protein involved in various cellular processes, has been associated with increased tumor cell migration, invasion, and treatment resistance. Methods: In this study, 223 bladder cancer cases were examined, and E-cadherin, vimentin, and galectin-3 expression was evaluated by immunohistochemical staining in tumor budding areas and invasive components. These markers were also correlated with clinicopathological parameters, including tumor grade and stage. Results: The results indicated a significant decrease in E-cadherin expression and an increase in vimentin staining in higher-grade and higher-stage tumors, supporting EMT involvement. Galectin-3 expression was notably higher in T1 high-grade tumors but decreased in T2 stage tumors. Despite this, no significant correlation was found between galectin-3 and E-cadherin or vimentin, suggesting a complex role of galectin-3 in EMT. Conclusions: High galectin-3 expression in T1 high-grade tumors highlights its potential role in early tumor progression and as a therapeutic target. However, the decrease in its expression in advanced stages underscores the need for further research to understand its multifaceted involvement in bladder cancer. These findings suggest that while galectin-3 may contribute to the EMT and early tumor progression, its exact role and potential as a therapeutic target require more detailed investigation.

Background/Objectives: Both benign and malignant thyroid lesions present as nodules. While thyroid nodules are less common in the pediatric population than in adults, their malignancy rates are considerably higher. Although the 10 mm cut-off for fine-needle aspiration cytology (FNAC) is commonly used for both adults and children, there is limited information regarding subcentimeter thyroid nodules in the pediatric population. The majority of published studies have focused on nodules measuring 1 cm or greater. This study aimed to compare the cytological diagnosis, ultrasonographic features, and histopathological outcomes of thyroid nodules in pediatric patients (under 21 years old), stratified by size (≤10 mm vs. >10 mm). Methods: We conducted a retrospective, single-center cohort study, evaluating 108 thyroid nodules from 98 patients. Nodule sizes were categorized into two groups, and their features were correlated with findings from FNAC using the Bethesda System for Reporting Thyroid Cytopathology and subsequent surgical histopathology. The risk of malignancy (ROM) was calculated for each Bethesda category. Results: A total of 108 nodules were evaluated, with 35 (32.4%) measuring ≤ 10 mm. The overall malignancy rate was 12%, with 14.3% in the ≤10 mm group and 11% in the >10 mm group. The difference was not statistically significant, and this finding indicates that small nodules can also harbor malignancy. Notably, all cases categorized as suspicious for malignancy or malignant by FNAC were confirmed to be malignant on histopathology (ROM = 100%). The Atypia of Undetermined Significance (AUS) category exhibited a malignancy rate of 60%, which is significantly higher than the rates reported in previous studies. Ultrasonographic features such as hypoechogenicity and microcalcifications were more prevalent in malignant nodules but lacked statistical significance. Conclusions: Our findings demonstrate that pediatric thyroid nodules, including those ≤10 mm, have a notable risk of malignancy. The high rate of malignancy in the AUS category suggests that the current Bethesda criteria, primarily designed for adults, may require re-evaluation for pediatric cases due to known differences in genetic profiles and disease behavior. Consequently, these pathological findings clearly demonstrate that FNAC indications in children should not be based solely on nodule size, and that a multidisciplinary approach guided by pediatric-specific guidelines should inform clinical management.

Aim: Nasopharyngeal carcinomas (NPCs) are often diagnosed through fine-needle aspiration biopsy (FNAB) samples from metastatic lymph nodes. The differential diagnosis of cervical mass lesions includes a broad spectrum of lesions, which can complicate the diagnostic process. This study aims to analyze the clinical and cytological features of 12 cases of undifferentiated nonkeratinizing NPC diagnosed from metastases and identify key morphological findings that may aid diagnosis. Method: This retrospective study included 12 cases of nasopharyngeal carcinoma diagnosed via fine-needle aspiration (FNA) in our department between 2021 and 2024. All cases were histologically classified as undifferentiated-type nasopharyngeal carcinoma. Clinical data of the cases were retrieved from the hospital information management system. Cytology smears were retrieved from the archives and re-evaluated in terms of cytomorphological characteristics. Results: Eight of the cases were male, and four were female. Their ages ranged from 23 to 80 years. All smears were cellular. In half of the cases (6 cases), the tumor cells formed cohesive clusters, whereas in 5 cases, the cells displayed loose cohesion. In 7 cases, the tumor cells exhibited large nuclei, with pleomorphism in 10 cases. In half of the cases, the nuclei were oval-shaped, followed by oval-to-round nuclei in four cases. Naked nuclei were observed in most cases (9/12). Nucleoli were prominent in 8 cases. In 10 cases, the cytoplasm was scant with indistinct borders. Conclusions: The cytologic diagnosis of NPC is complex and requires a multifaceted approach. FNA of cervical lymph nodes is a valuable diagnostic tool, but careful interpretation is crucial. The presence of cells exhibiting a mixed pattern—forming clusters as well as appearing isolated cells—characterized by large pleomorphic nuclei, prominent nucleoli, and scant cytoplasm, particularly in samples obtained from cervical lymph nodes, constitutes a significant clue in cytological diagnosis.