Defining the lymph node burden in a Northern European population without malignancy: the potential effect of geography in determining a need for FNA?

Abstract

Data from the USA suggest that morphological specificity is insufficient to permit an assumption of malignancy in nodal staging with endoscopic ultrasound (EUS). This may not hold true elsewhere as the background lymph node burden may vary in different geographic regions. We aimed to assess the prevalence and features of mediastinal and abdominal lymph nodes at EUS in a Northern European population without malignant disease. A total of 129 consecutive patients without malignant disease referred for radial EUS were prospectively evaluated for the prevalence and echo features of lymph nodes in the mediastinum and upper abdomen. Sixty-two percent of patients had mediastinal lymph nodes and 17% had abdominal nodes at EUS. A mean of 1.4 (standard deviation 1.3, range 0-8) nodes were found per patient. No celiac nodes were seen. The majority of detected nodes were 0.5 cm or less in short axis, had oval shape, centrally echogenic pattern, and indistinct borders. The most common node locations were the subcarinal and paraesophageal areas, and the hepatoduodenal ligament. In multivariate analysis mediastinal lymphadenopathy was related to body mass index and abdominal lymphadenopathy to acute pancreatitis. The occurence of mediastinal lymphadenopathy is markedly lower in Northern Europeans than reported for US patients. Celiac nodes are extremely rare in patients without malignancy. The majority of nodes have a width of 0.5 cm or less, have oval shape, centrally echogenic pattern, and indistinct borders. The characterization of the background lymph node burden may improve the selection of lymph nodes for fine needle aspiration.

Prevalence and echo features of mediastinal lymph nodes in EUS for non-malignant indications: a prospective study in a Southern European Population

“…In conclusion, this study documented a higher prevalence of mediastinal lymph nodes in a Southern European population than previously reported in Northern Europe, in patients with no evidence of oncologic disease 15 . This higher prevalence may negatively influence the specificity and positive predictive value for malignancy of mediastinal lymph node staging by EUS, which may be particularly relevant in esophageal and pulmonary cancer staging.…”

“…In this study, we prospectively examined 75 patients who underwent EUS for non-malignant disease, looking for mediastinal lymph nodes. We found a prevalence of mediastinal lymph nodes of 72 % (54/75), higher than the one reported in Northern Europe by Kalaitzakis et al 15 and lower than that documented in Indianapolis, United States, by Wiersema et al 16 . We hypothesized that this could be related to the higher prevalence of tuberculosis in Southern Europe versus Northern Europe 17 .…”

“… 3 Autopsy and CT studies from different countries have shown significant heterogeneity regarding prevalence and features of mediastinal lymph nodes 12 13 14 . The only two studies based on EUS which analyzed mediastinal lymph node burden in populations without underlying malignant disease showed a marked variation among United States (Indiana) and Northern European populations (Sweden and UK) 15 16 .…”