Clinicopathological analysis of early gastric cancer with solitary lymph node metastasis

Background: The sentinel node concept has not yet been established in gastric cancer. Methods: Fifty-four patients with early gastric cancer who had only one lymph node metastasis were regarded retrospectively as patients with a possible sentinel node metastasis, and the morphological features of these nodes were assessed. The level I nodes in seven patients with a possible skip metastasis at routine haematoxylin and eosin staining were re-examined using cytokeratin (CK) immunostaining. Results: The shape of the gastric cancer lesion could be examined in 53 of the patients; more than one-third (20 of 53) were microfocal type. Concerning the intranodal cancer foci, the marginal sinus type was found in 32 affected nodes, medullary sinus type in 14 and mixed type in seven. Forty-three per cent of suspected sentinel nodes were the largest in size among all nodes from the station. CK immunostaining of seven non-metastatic nodes with haematoxylin and eosin revealed that three were CK positive. Conclusion: These findings suggest that possible sentinel nodes detected by conventional means may not always be primary portions of any metastasis. Adoption of sentinel node biopsy in gastric cancer must await the development of improved procedures for diagnosis during surgery.