Histology Combined with Cytology by Endoscopic Ultrasound-Guided Fine Needle Aspiration for the Diagnosis of Solid Pancreatic Mass and Intra-Abdominal Lymphadenopathy

BACKGROUND/AIMS Small core biopsy samples can occasionally be obtained with conventional endoscopic ultrasonography-guided fine needle aspiration (EUS-FNA). Although most studies have focused on the cytological analysis of specimens, data regarding histological assessment is scarce. The aim of this study was to determine whether core biopsies by conventional EUS-FNA could increase the accuracy of EUS-guided sampling when combined with cytology in the absence of an on-site cytopathologist. METHODS In the 95 consecutive patients (98 lesions) undergoing EUS-FNA of solid pancreatic masses and intra-abdominal lymphadenopathy, tissue coils from the needle were harvested for histology, and residual tissue was examined by cytology. RESULTS Adequate samples were obtained by EUS-FNA cytology, histology, and combined cytology-histology in 91.8%, 65.3%, and 94.8% of patients, respectively. From the pancreas (n=67), adequate samples for histology were obtained by EUS-FNA in 68.7% of cases, compared with 58.0% from non-pancreatic cases (n=31), respectively (p>0.05). The overall sensitivity and accuracy of EUS-FNA was 78.0% and 81.6% for cytology alone, 63.4% and 69.4% for histology alone, and 84.1% and 86.7% for combined cytology-histology, respectively. CONCLUSIONS Combined cytology and histology analysis for diagnosing pancreatic masses and intra-abdominal lymphadenopathy may increase the diagnostic yield of conventional EUS-FNA without on-site cytology.