A 64-year-old woman comes to the office for evaluation of a vulvar lesion. The patient has had a vulvar plaque for the past year that has slowly increased in size. She underwent menopause at age 52 and has a 30-year smoking history. Vital signs are normal. Physical examination shows a 1-cm nonfriable, white plaque on the right labia majora. The remainder of the physical examination is normal. A biopsy of the lesion is performed and shows squamous cell carcinoma. A sentinel lymph node biopsy is planned for cancer staging. This procedure should target which of the following lymph nodes?
Primary lymph node drainage of the female reproductive system | |
Uterus |
|
Cervix |
|
Vagina |
|
Vulva |
|
Ovaries |
|
This patient has squamous cell carcinoma (SCC), the most common type of vulvar cancer. Patients with vulvar cancer typically present with either an ulcerative lesion or plaque on the labia. Risk factors include chronic human papillomavirus infection, prior vulvar lichen sclerosus, and tobacco use.
Like most carcinomas, vulvar carcinoma can spread directly to adjacent structures (eg, perineum, vagina) or from the primary site to regional lymph nodes via lymphatic drainage. Therefore, initial cancer staging typically assesses for tumor spread in the first lymph nodes to drain the primary tumor site (ie, sentinel lymph node biopsy) because they are the most likely to have tumor involvement. The lymphatic drainage of the vulva is initially to the inguinofemoral nodes, which consists of a superficial inguinal and a deeper femoral node.
(Choices A and B) Lymph from the uterine corpus and inguinal nodes (which drain the lower extremities, buttocks, and external genitalia) subsequently drain to the external iliac nodes. The external iliac nodes and internal iliac nodes both drain to the common iliac nodes.
(Choice D) The bladder, uterus, and portions of the cervix can drain to the obturator nodes, which are located in the obturator fossa medial to the external iliac vessels. The obturator nodes are 1 of 3 pelvic lymph node groups (ie, obturator, external iliac, internal iliac) that together drain the pelvis, lower extremities, and lower abdominal wall.
(Choice E) Lymph from the ovary and common iliac node drain to the paraaortic lymph nodes.
(Choice F) The anal canal and rectum drain to the presacral lymph nodes.
Educational objective:
Squamous cell carcinoma of the vulva can metastasize via lymphatic drainage. The vulva first drains to the inguinofemoral nodes of the groin, which should be the target for sentinel lymph node biopsy because they are the most likely lymph nodes to have tumor involvement.