SLNB and the importance of micrometastases in vulvar squamous cell carcinoma

With the exception of patients with tumors smaller than 2 cm and infiltration less than 1 mm, standard treatment for squamous cell carcinomas of the vulva includes ipsi- or bilateral inguinofemoral lymph node dissection. However, with only 20% of early stage patients presenting with lymph node metastases in the groin, the majority of these patients do not gain from the procedure, but are at risk of its complications and detriments. The sentinel lymph node biopsy (SLNB) method targets the lymph nodes most likely to contain metastasis and has proven high accuracy in predicting the absence of metastasis in non-sentinel lymph nodes when found negative on pathologic examination. The SLNB further provides for a more thorough examination of the harvested lymph nodes and hence increases the detection of micrometastases. Although the clinical significance of micrometastases is controversial, reports on patients with micrometastasis suffering recurrence emerge, making the importance of detecting micrometastases in the pathologic examination of the sentinel lymph nodes evident. Appreciating its limitations, the sentinel lymph node procedure shows evidence of evolving into a feasible and safe procedure in the hands of experienced surgeons, pathologists and nuclear medicine physicians in early stage vulvar carcinoma patients. Still, larger multicenter trials are needed to assess its accuracy and safety.