Endoscopic ultrasound (EUS), combined with fine-needle biopsy (FNB) and histopathological examination, represents a key diagnostic tool for the assessment of deep-seated lymphadenopathy (mediastinal or abdominal). This technique provides excellent diagnostic accuracy, particularly in differentiating benign from malignant etiologies, thereby guiding appropriate therapeutic strategies. The aim of this study was to evaluate the contribution of EUS-guided fine needle aspiration (EUS-FNA) in the workup of mediastinal and abdominal lymphadenopathy.

We conducted a retrospective descriptive study over a 4-year period (January 2020 – December 2024) in the Department of Hepato-Gastroenterology. All patients who underwent EUS-guided FNB for lymphadenopathy were included. Exclusion criteria were: a prior diagnosis of granulomatous disease, known metastatic digestive cancer, and cases of inaccessible or sub-centimetric lymphadenopathy.

Out of 192 EUS procedures performed, 22 patients were included. The mean age was 53 years [20–82], with a male-to-female ratio of 0.8. The main presenting symptom was obstructive jaundice (45%), sometimes associated with epigastric pain (9%). Additional clinical findings included weight loss (4 cases), incidental discovery during the evaluation of a pancreatic mass (3 cases), hemorrhagic syndrome (1 case), dyspnea with hemoptysis (1 case), and isolated abdominal pain (1 case).

Initial imaging (thoraco-abdominopelvic CT in 85% of cases, MRCP in 20%) revealed: confluent mediastinal and/or abdominal lymphadenopathy in 41% of cases, pancreatic mass with lymph node involvement in 32%, common bile duct thickening in 18%, and gastric wall thickening in 2 cases.

EUS-FNB targeted abdominal lymph nodes in 64% of cases, mediastinal in 23%, and combined abdominal and mediastinal in 14%. Abdominal lymph node locations included hepatic hilum (50%), celiac (36%), and perigastric (21%); mediastinal lymph nodes were mainly at station 7 (85%) and station 9 (15%). The mean lymph node size was 23 mm [10–45]. Needles used were 20G (55%) and 22G (45%). The number of passes per biopsy ranged from 1 to 3, with fanning technique applied.

Histopathological analysis yielded malignant etiologies in 36% of cases (5 pancreatic adenocarcinomas, 1 lymphoma, 1 neuroendocrine carcinoma, 1 undifferentiated carcinoma), granulomatous disease in 18% (2 sarcoidosis, 2 tuberculosis), reactive lymphadenitis in 41%, and non-contributive hemorrhagic material in 5%. No procedure-related complications were reported.

EUS combined with FNB has emerged as the reference examination for the assessment of deep-seated lymphadenopathy, particularly mediastinal and abdominal. In our series, diagnostic yield reached 95% at the first histopathological analysis. This minimally invasive and well-tolerated technique represents an essential tool for ruling out malignancy or identifying specific disease processes, thereby allowing targeted therapeutic management.