Endoscopic Ultrasound-Guided Fine Needle Aspiration Cytology versus Fine Needle Biopsy—A Prospective Comparative Study

Introduction: Endoscopic ultrasound guided tissue acquisition (EUS- TA) has become the mainstay for tissue diagnosis of abdominal mass lesions. Two widely used and accepted methods for obtaining diagnostic material, namely fine needle aspiration cytology (EUS-FNAC) and needle core biopsy (EUS-FNB) have distinct advantages and dis-advantages. We compared the diagnostic accuracy of EUS FNAC without on-site pathology and EUS FNB in solid gastrointestinal and extra-intestinal abdominal masses taken within the same endoscopic session.

Methods: In this prospective observational study, we included patients undergoing EUS FNAC and EUS FNB for the diagnosis solid intra-abdominal masses. Sample size was calculated based on available literature. Location, origin, dimensions of the intraabdominal masses, and number of passes taken were recorded. Adequacy of the FNB specimen was judged visually, while adequacy of FNA was judged under microscope. Histological diagnosis from FNB specimens was considered standard to assess diagnostic accuracy of EUS FNA.

Results: Of the 58 patients included, 50% of patients were females with a mean age of 53.91 ± 17.16 years. 19 pancreatic masses (32.7 %), 3 gastric mass lesions (5.1%), 1 adrenal mass (1.7%), 1 liver mass (1.7%), 3 gall bladder masses (5.1 %), and 31 lymph nodal masses (53.4%) were sampled. Sample was adequate in all specimens. With EUS FNB, malignancy was diagnosed in 33/58 (56.8%), benign diseases in 24/58 (41.3%), and 1/58 (1.7%) was inconclusive. Number of passes was more in the EUS FNA group compared to EUS FNB, but not statistically significant. Sensitivity and specificity of EUS FNA was found to be 92.4% and 100% respectively. Diagnostic accuracy of EUS FNA was 93.1% and when compared with EUS FNB, no statistically significant difference was noted.

Conclusion: EUS FNA is comparable to EUS FNB for diagnosis of intraabdominal masses in terms of diagnostic accuracy, sample adequacy, number of passes, and safety. In resource constraint settings, EUS FNA alone may be sufficient for diagnosis, with EUS FNB reserved for cases needing immunohistochemistry.

Publication History

Article published online:
22 April 2024