A 72-year-old woman, gravida 2, para 2, comes to the gynecologist reporting a vulvar lesio… — USMLE Step 2 CK

A $72$ -year-old woman, gravida $2$ , para $2$ , comes to the gynecologist reporting a vulvar lesion that she first noticed $4$ months ago. She states that the area is occasionally pruritic and bleeds slightly when wiped. Her past medical history is notable for lichen sclerosus, which was diagnosed $10$ years ago and is managed with intermittent topical clobetasol. Menopause occurred at age $51$ . On physical examination, the vagina and cervix appear atrophic. On the right labium majus, approximately $4$ cm lateral to the midline, there is a $2.5$ cm, firm, ulcerated, unifocal nodule. There are no palpable inguinal lymph nodes. A punch biopsy of the nodule confirms invasive squamous cell carcinoma with a depth of invasion of $3.5$ mm. Which of the following is the most appropriate next step in management?

Radical local excision with right inguinofemoral lymph node evaluationAnswer
B
Radical local excision with bilateral inguinofemoral lymph node evaluation
C
Radical local excision without lymph node evaluation
D
Topical application of imiquimod $5\%$ cream
E
Primary external beam radiotherapy to the vulva and groins

Answer

Radical local excision with right inguinofemoral lymph node evaluation

For early-stage invasive squamous cell carcinoma of the vulva, management is dictated by the size, depth of invasion, and location of the lesion. This patient has a Stage IB tumor because the depth of invasion (

3.5

mm) exceeds

1.0

mm and the size (

2.5

cm) exceeds

2

cm. Any vulvar cancer with

> 1

mm depth of invasion requires inguinofemoral lymph node evaluation due to the risk of lymphatic metastasis. Because her lesion is clearly lateral (located

4

cm from the midline on the right labium majus), lymphatic drainage is predominantly unilateral. Therefore, radical local excision of the primary tumor combined with an ipsilateral (right) inguinofemoral lymph node evaluation (via complete dissection or sentinel lymph node biopsy) is the most appropriate next step.

Step-by-Step Solution

Determine the stage of the vulvar cancer based on biopsy and physical examination findings.

The tumor is

2.5

cm in size with a depth of invasion of

3.5

mm.

Tumor size

> 2

cm and depth

> 1

mm classifies this as Stage IB vulvar carcinoma, which carries a substantial risk of lymphatic metastasis.

Identify the anatomic location of the lesion relative to the midline.

The lesion is unifocal and located on the right labium majus,

4

cm lateral to the midline.

Lesions situated

> 2

cm from the midline are classified as lateral and primarily drain to the ipsilateral inguinofemoral lymph nodes, whereas midline lesions drain bilaterally.

Select the appropriate surgical intervention based on staging and anatomic location.

Radical local excision of the primary tumor combined with an ipsilateral (right) inguinofemoral lymph node evaluation.

The standard of care for lateral Stage IB vulvar cancer is wide excision with ipsilateral node assessment to evaluate for metastasis while avoiding the morbidity of unnecessary bilateral dissection.

Key Concept

Management of early-stage invasive vulvar cancer requires radical local excision. The need for lymph node evaluation depends on the depth of invasion (

> 1

mm requires assessment), and the laterality of the evaluation (ipsilateral vs. bilateral) depends on the tumor's distance from the midline (lateral lesions

\ge 2

cm from the midline require only ipsilateral dissection).

Estimated Time:1m 30s

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