Abstract Introduction Current clinical practice guidelines recommend molecular profiling for patients with pancreatic ductal adenocarcinoma (PDAC). However, endoscopic ultrasound–guided small specimens are often insufficient for next‐generation sequencing (NGS). In this study, the impact of a standardized protocol designed to optimize tissue acquisition for NGS was evaluated. Methods Quality assurance data from patients with suspected PDAC who underwent endoscopic ultrasound–guided tissue acquisition for NGS was retrospectively analyzed. A standardized workflow incorporating rapid onsite evaluation using predefined adequacy criteria, dedicated tissue procurement for cell block preparation, multidisciplinary communication, and prospective monitoring of molecular outcomes were evaluated using a successful NGS result as the primary endpoint. Results Of the 61 patients with confirmed PDAC by cytology, 49 specimens (80.3%) were deemed adequate for NGS during rapid onsite evaluation. Forty‐one specimens with a median tumor fraction of 30% underwent NGS. Median DNA and RNA yields were 20.8 ng/µL and 19.7 ng/µL, respectively. DNA‐based NGS was successful in 39 cases (95.1%), whereas RNA‐based fusion analysis succeeded in 22 cases (53.7%). Median turnaround time from specimen receipt to NGS reporting was 10 business days. Conclusions A standardized molecular adequacy protocol achieved high DNA sequencing success but did not substantially improve overall specimen adequacy compared with prior institutional experience. Intrinsic biologic features of PDAC, including low tumor cellularity and abundant desmoplastic stroma and nonneoplastic elements remain the principal barriers to molecular profiling. Future efforts that focus on improving tumor enrichment and optimizing RNA preservation may expand precision oncology access to patients with PDAC.
This news section is written by a medical journalist and offers Cancer Cytopathology readers timely information on events, issues, and personalities of interest to the subspecialty. In part one of a two‐part series on research in radically altered living conditions, experiments in real and simulated weightlessness have opened new opportunities for cancer investigators.
Abstract Background Pancreatic duct abnormalities may be the only imaging manifestation of neoplasia, but the diagnostic utility of duct cytology is unclear. The objective of this study was to evaluate cytology in relation to duct diameter, ancillary studies, and histologic follow‐up. Methods The authors retrospectively analyzed 158 pancreatic duct cytology specimens from 144 patients obtained during 2014–2024. Main duct dilatation (MDD) was stratified by diameter. Cytologic diagnosis, fluid biochemistry, next‐generation sequencing (NGS), and cytology–histology correlation were assessed. Results Of 158 specimens, 145 (91.8%) had MDD, and 13 (8.2%) had stricture/stenosis. Sampling comprised 133 fine‐needle aspirations (84.2%) and 25 brushings (15.8%). In total, 98 specimens (62.0%) were nondiagnostic or negative. Cytologic diagnosis distributions did not differ among MDD groups ( p = .316). Carcinoembryonic antigen (CEA) was available for 93 specimens; 20 (21.5%) exceeded 192 ng/mL, including nine with nondiagnostic or atypical cytology. Of 60 specimens with interpretable NGS, 31 (51.7%) had mucinous‐associated mutations, and nine (15.0%) had high‐risk alterations. Histology was available for 51 patients; all 14 patients with neoplastic–other cytology had confirmed neoplasms. Adenocarcinoma was identified in 14 patients: one of 10 was nondiagnostic, four of seven were atypical, two of 14 were neoplastic–other, one of two was suspicious, and six of seven were positive. Cytology alone (neoplastic–other or worse) was 64.7% sensitive and 94.1% specific for neoplasia; adding available CEA and then NGS increased sensitivity to 73.5% and 91.2%, respectively, with 88.2% specificity. Conclusions Pancreatic duct cytology was highly specific but only moderately sensitive for neoplasia and did not differ by MDD severity. Although there was a modest decrease in specificity, CEA and NGS substantially improved sensitivity, supporting their adjunctive value in cytologically indeterminate cases.
Abstract Accurate classification of lung tumors in cytology specimens and small biopsies remains a diagnostic challenge because of limited cellularity, preanalytical variables, and significant morphologic overlap among entities. This review summarizes key cytomorphologic characteristics and practical immunocytochemical strategies, and common diagnostic pitfalls encountered in the evaluation of non‐small cell lung carcinoma, small cell lung carcinoma, neuroendocrine tumors, secondary pulmonary neoplasms, and uncommon thoracic entities in endobronchial ultrasound‐guided transbronchial needle aspiration and fine‐needle aspiration samples. Particular emphasis is placed on the appropriate use of limited immunohistochemical panels to optimize tumor subtyping while preserving material for molecular testing. Diagnostic challenges such as crush artifact, necrosis, reactive mimics, overlapping morphologic patterns, and the risk of misclassification of rare tumors are addressed with practical guidance for differential diagnosis. By integrating morphologic assessment with ancillary testing, cytopathologists can achieve accurate tumor subtyping, distinguish mimics, and provide precise diagnoses that guide clinical management and selection of targeted therapies.
Abstract Background Immunohistochemistry (IHC) is essential for tumor subtyping and predictive biomarker analysis in non–small cell lung carcinoma (NSCLC). When only cytological material is available and no concurrent biopsy or cell block exists, immunocytochemistry (ICC) may need to be performed on slides prepared using diverse fixation protocols, introducing substantial pre‐analytical variability. Methods Seven laboratories representing commonly used cytology fixation protocols were selected based on an exploratory global survey of 63 institutions. Two central laboratories prepared direct smears, cytospins and provided cells in PreservCyt from specimens with confirmed marker expression using the selected fixation protocols. Materials were distributed for immunocytochemical demonstration of TTF‐1, p40, ALK , and ROS1 according to local protocols. Digitized slides were independently evaluated using standardized four‐tier scoring criteria. Result A total of 105 stained slides from 17 study runs were assessed. Delaunay‐fixed, Papanicolaou‐stained, and methanol‐fixed polyethylene glycol‐coated preparations demonstrated consistently superior ICC performance compared with other evaluated fixation protocols. In contrast, high rates of suboptimal staining were observed with PreservCyt fixation (81.8%) and air‐dried preparations (58.8%). Conclusions This study demonstrates that fixation protocol significantly impacts ICC performance on non–cell block cytological preparations. The observed fixation‐dependent differences underscore the need for harmonized pre‐analytical practices, robust local validation, and external quality assessment.
