The significance of histologic findings in predicting nodal metastases in invasive squamous cell carcinoma of the vulva.

The significance of tumor differentiation, depth of stromal penetration, and vascular channel involvement in predicting nodal metastases was studied in 62 patients with invasive squamous cell carcinoma of the vulva treated with radical vulvectomy and bilateral inguinal and femoral lymphadenectomy. The pattern of arrangement of vulvar neoplastic cells at the interface with stroma was used as a criterion for histologic grading. Patients with less differentiated tumors had a higher incidence of nodal metastasis within each stage of disease. No nodal metastases were noted in patients with Grade III tumors who had Stage I disease. No well-differentiated tumor with less than 5 mm of stromal penetration was associated with nodal metastases. In this study, the degree of tumor differentiation and the depth of stromal penetration were important predictors of nodal metastases. It was concluded that a subgroup of patients with Stage I well-differentiated vulvar carcinoma invading less than 5 mm into the underlying stroma may benefit by less radical surgery without compromising cure.