Background: EUS-guided fine needle aspiration (EUS-FNA) has significantly increased the diagnostic capability of EUS. FNA can also be helpful in the diagnosis of non-GI disorders. The role of EUS-FNA in the diagnosis of idiopathic abdominal masses has not been determined. This study evaluated the diagnostic accuracy of EUS-FNA of abdominal masses of unknown cause and its impact on subsequent evaluation and therapy.
Methods: Thirty-four patients from 5 tertiary referral centers (21 women, 13 men; mean age 54 years, range 27-72 years) with idiopathic abdominal masses underwent EUS-FNA. Presenting symptoms included the following: pain (29 patients), weight loss (15), altered bowel habits (7), nausea/vomiting (6), abnormal liver function tests (4), palpable mass (4), and urinary retention (1). Four patients had a history of intra-abdominal cancer (2 cervical, 1 ovarian, 1 colon). A final diagnosis by EUS-FNA, surgery, autopsy, or long-term follow-up was available in all patients. Abdominal masses were classified into 3 disease categories: infectious, benign/inflammatory, and malignant.
Results: Final diagnosis included infectious (5), benign/inflammatory (6), and malignant (23) abdominal mass. Overall, EUS-FNA established a tissue diagnosis in 29 of 34 patients (85%) in all 3 categories (infectious, 80%; benign/inflammatory, 67%; malignant, 91%). EUS-FNA was instrumental in directing subsequent evaluation in 29 patients (85%) and therapy in 26 (77%). The number of fine needle passes for adequate tissue sampling was lower for nonmalignant (2.2-3.2) versus malignant diseases (4.6). One complication occurred (perirectal abscess) and was treated successfully with antibiotics.
Conclusions: EUS-FNA of idiopathic abdominal masses is safe and accurate and helps to guide subsequent evaluation and therapy in the majority of patients. The most common and promising area seems to be EUS-FNA of malignant abdominal masses. Transluminal EUS-FNA provides minimally invasive tissue sampling and obviates the need for exploratory laparotomy.