Anatomy and biopsy of sentinel lymph nodes

Lymphangiograms performed via the dorsal lymphatics of the penis demonstrate drainage into a specific lymph node center, the so-called sentinel lymph node, which is located close to the superficial epigastric vein between the latter and the superficial external pudendal vein. Anatomically, clinically, and pathologically, the sentinel lymph node is the first site of metastasis and often is the only lymph node involved. We recommend preliminary bilateral sentinel lymph node biopsy, with inguinofemoral dissection being performed only when this node is involved. If the biopsies are negative for metastases, no further surgical therapy is immediately indicated, and the patient needs to be observed closely with monthly examination for 1 year and examination every 2 months for 3 years. The clinical staging of cancer of the penis needs a new review for further evaluation of different modalities of treatment. Sentinel lymph node biopsy must not be used to determine whether node dissection is needed in patients with evident clinically positive nodes. Also, the concept of sentinel lymph node should not be applied in the management of patients who will not be available for frequent follow-up. If during physical examination, suspect lymph nodes are found other than the classic sentinel node, these lymph nodes must be removed for staging and subsequent treatment planned according to the histologic report.