The aim of our study was to evaluate the contribution of fine-needle biopsy (FNB) coupled with ultrasound endoscopy for the exploration and diagnosis of mediastinal and abdominal lymph nodes.

This was a descriptive retrospective study over a period of 3 years from July 2021 to March 2024 within a hepatogastroenterology department at Ibn Sina University Hospital in Rabat, including all patients who underwent fine-needle biopsy (FNB) of lymphadenopathy under endoscopic ultrasound. Exclusion criteria included patients already diagnosed with granulomatosis, or with metastatic digestive cancer, and those with lymph nodes that are difficult to access to fine-needle biopsy under endoscopic ultrasound or less than one centimeter in size.

A total of 22 patients were included during the study period out of a total of 274 patients that underwent ultra sound endoscopy. Patients were 10 males and 12 females with a mean age of 53 years (range: 20-82).

The circumstances of discovery were as follows: in 45% of cases (n=10), there was cholestatic jaundice, associated with epigastric pain in 9% of cases. Four patients presented with weight loss, three cases were incidentally discovered during exploration of a pancreatic mass, one case presented with hemorrhagic syndrome, one case with dyspnea and hemoptysis, and one case with algic syndrome.

Imaging was performed in all patients. Abdominal-pelvic CT scans were conducted in 85% of patients, and MRCP in 20% of patients. Imaging revealed in 41% of cases a cluster of mediastinal lymphadenopathies, associated or not with abdominal lymphadenopathies, in 32% of cases, the presence of a pancreatic lesion with lymph node involvement; and in 18% of cases, thickening of the main bile duct. Two cases of gastric thickening were noted.

The site of fine-needle biopsy was abdominal in 64% of cases (n=14), abdominal and mediastinal in 14% (n=3), and mediastinal in 23% (n=5). For abdominal lymph nodes, 50% were located at the hepatic hilum, 36% at the celiac level, and 21% at the perigastric level. For mediastinal lymph nodes, fine-needle biopsy was performed at station 7 in 85% of cases and at station 9 in 15% of cases.

The average size of lymph nodes was 23mm [range: 10-45]. The needle gauge used was 20G in 55% of cases and 22G in 45% of cases. The number of passages ranged from 1 to 3 per biopsy with fanning technique.

The diagnosis was malignant in 36% of cases: 5 cases of pancreatic adenocarcinoma, 1 case of lymphoma, 1 case of neuroendocrine carcinoma, and 1 case of undifferentiated carcinoma. In 18% of cases, biopsy results favored granulomatosis in 4 patients: 2 cases of sarcoidosis and 2 cases of tuberculosis. Finally, reactive adenitis was found in 41% of cases, and hemorrhagic content was observed in 5% of cases.

It is noteworthy that no complications related to FNB during EUS were observed.

Endoscopic ultrasound coupled with FNB is at the forefront for diagnosing deep lymph nodes, whether they are mediastinal or abdominal. In our study, the diagnostic yield was 95% after initial histopathological analysis.

This technique remains minimally invasive and effective. It allows not only to exclude metastatic lymph nodes but also the initiation of specific treatment once the pathology is documented.