Clinical significance of immunohistochemically detectable lymph node metastasis in adenocarcinoma of the ampulla of Vater

BACKGROUND: The aim of this study was to assess the impact of immunohistochemically identified lymph node metastasis on survival in patients with carcinoma of the ampulla of Vater. METHODS: Three hundred and twenty-six regional lymph nodes dissected from pancreatoduodenectomy specimens from 25 patients with ampulla of Vater carcinoma were immunostained with anticytokeratin antibody (CAM 5.2). The clinicopathological significance of immunohistochemically detectable lymph node metastasis was evaluated and compared with that of other potential prognostic factors. RESULTS: The frequency of lymph node involvement in relation to the total number of dissected lymph nodes increased from 5.5 per cent (18 of 326) using haematoxylin and eosin staining to 9.5 per cent (31 of 326) using cytokeratin immunostaining (P < 0.001). Lymph node involvement was revealed by haematoxylin and eosin staining in eight of 25 patients and by cytokeratin immunostaining in 11 of 25 patients (P = 0.006). Absence of immunohistochemically detectable lymph node metastasis was identified as an independent predictor of improved postoperative survival. CONCLUSION: Immunostaining of dissected lymph nodes adds additional information to data obtained by conventional haematoxylin and eosin staining when determining the prognosis of patients with carcinoma of the ampulla of Vater.