Histologic parameters of vulvar invasive carcinoma and lymph node metastases

We evaluated seven histologic parameters (tumor diameter, histologic grading, depth of stromal invasion, vascular invasion, pattern of invasion, lymphoplasmocytic infiltration and amount of necrosis) of 50 cases of vulvar invasive carcinoma to assess their correlation with groin lymph node metastases. Of 50 patients, 25 had groin lymph node metastases. No lymph node metastasis was found in four cases with depth of invasion < or = 2.0 mm. Among the 31 patients with vascular invasion, 23 (74%) had positive nodes, whereas lymph nodes were metastatic only in two of the 19 patients (10%) without vascular invasion. At univariate analysis, performed with Fisher's exact method, all the parameters considered, except pattern of invasion and amount of necrosis, were significantly associated (P < .05) with lymph node metastases. However, after adjustment by multiple logistic regression for the variables statistically significant at univariate level, only the presence of vascular invasion was significantly associated with nodal involvement and tumor diameter was borderline, whereas the effect of the other variables was almost completely explained by confounding.