Isolated tumor cells in regional lymph nodes in patients with adenocarcinoma of the esophagogastric junction might represent part of true metastases.

Regional lymph node metastases in patients with carcinoma of the esophagogastric junction (EGJ) are an important prognostic factor. According to the tumor, node, and metastasis classification, isolated tumor cells (ITCs) are single tumor cells or small clusters of tumor cells not exceeding 0.2 mm. Tumor clusters >0.2 mm are classified as metastases. The significance of lymph nodes with ITCs is unclear, although not contributing to the pN category. The aim of this study was to determine the prevalence of regional lymph nodes with ITCs on the primary hematoxylin and eosin-stained slide and to examine how often deeper sections reveal a true metastasis. The study included surgical specimens of 126 patients with adenocarcinoma of the EGJ. Lymph nodes with ITCs were identified. Additional sections were cut and stained with hematoxylin and eosin and with cytokeratin. All slides were evaluated for the presence of tumor cells, and it was determined whether the criteria for a metastasis were met on the additional sections. ITCs were detected in 59 (1.7%) of 3454 lymph nodes and in 41 (32.5%) of 126 patients. In 29 (49.2%) lymph nodes with ITCs on the primary slide, further sections resulted in a changed status from ITCs to a metastasis. In 7 (17.1%) of 41 patients, the pN category was changed. In patients with adenocarcinoma of the EGJ, the presence of ITCs in regional lymph nodes is a common observation. ITCs often represent part of a real metastasis. To obtain a pN category as accurate as possible, we strongly recommend thorough examination of regional lymph nodes with additional sections when ITCs are observed.