Endoscopic ultrasound-guided fine needle aspiration biopsy — diagnostic principles and workup

Endoscopic ultrasound-guided fine needle aspiration biopsy (EUS-FNAB) is a well-recognized diagnostic tool of high sensitivity (60–95%) and specificity (85–100%) for diagnosing solid, cystic, and solid-cystic lesions in the gastrointestinal tract (esophagus, stomach, and intestines) or pancreas and biliary tract. The specificity may be lower though for lesions of smaller size or of difficult location. The quality of received tissue increases with the endoscopist’s experience and proper application of the technique and the needles (e.g. vacuum aspiration); the key point for the diagnosis is high level cytomorphologic analysis performed by an experienced pathologist.