Detection of Lymphovascular Invasion in Vulvar Cancer by D2-40 (Podoplanin) as a Predictor for Inguinal Lymph Node Metastases

Background: Lymphatic vessel invasion (LVI) plays a major role in the spread of vulvar cancer and predicts regional lymph node metastasis. D2-40, a monoclonal immunohistochemical marker might be able to increase the detection rate of LVI compared to conventional hematoxylin-eosin (HE) staining. The aim of the study was to evaluate the suitability of D2-40 for the prediction of regional lymph node metastases. Patients and Methods: Immunohistochemical staining with D2-40 was performed on formalin-fixed, paraffin-embedded tissue sections of 32 patients with squamous cell carcinoma of the vulva. Slides were screened for the presence of LVI. Correlation with clini-co-pathological features including LVI as retrieved by routine HE-stained sections was assessed. Results: Immunostaining with D2-40 significantly (p = 0.019) increased the frequency of detection of lymphatic invasion compared to conventional HE staining. LVI was correctly identified by D2-40 (D2-40+ LVI) in 65.6% of tumor specimens as compared to 40.6% by routine HE staining (HE+ LVI). D2-40+ LVI significantly (p = 0.026) predicted inguinal lymph node metastases. Conclusions: Immunostaining with D2-40 significantly increased the frequency of detection of lymphatic invasion compared to conventional HE staining in squamous cell carcinomas of the vulva. D2-40+ LVI is a strong predictor for inguinal lymph node metastases.