(A) Observation
(B) Prophylactic radiation therapy
(C) Sentinel node biopsy
(D) Modified radical neck dissection
(E) Radical neck dissection

The correct response is Option C.

This patient has a T3 melanoma, which is defined as a tumor that has a Breslow’s thickness between 1.5 and 4 mm, or is designated as Clark’s level IV. Because this melanoma is of intermediate thickness and there are no palpable regional lymph nodes, it is classified as Stage II. In addition to local excision and superficial parotidectomy, sentinel node biopsy is currently recommended to rule out the presence of micrometastases in patients with these lesions.
Lymphatic invasion has the greatest influence on prognosis, but the amount of tumor burden within the lymphatic system also affects prognosis. Approximately 30% to 40% of patients with melanomas of intermediate thickness and no palpable lymph nodes in the neck have subclinical nodal micrometastases; lymph node dissection results in increased survival in this subgroup. However, performing elective lymph node dissection in all of these patients, without identifying those who would benefit most, would subject the remaining 60% to 70% who do not have demonstrable micrometastases to unnecessary morbidity without increasing survival advantage. Sentinel lymphadenectomy using vital blue dye and radiocolloid for mapping can be performed to identify the subgroup in which regional lymphadenectomy should be performed.

Clinical observation followed by neck dissection when regional lymph nodes become apparent is not an acceptable option.

Although prophylactic radiation therapy has been shown to produce benefits similar to elective lymph node dissection in patients with tumors of intermediate thickness, it subjects approximately 66% of patients to unnecessary morbidity. As other means of identifying micrometastases become available, radiation therapy should be considered as a valid treatment alternative in selected patients.

Neck dissection is indicated for patients with stage II tumors who have micrometastases identified via sentinel lymphadenectomy and in patients who have stage III melanoma. The dissection should include levels I through V as well as any other nodal groups that may be at risk. Neck dissection has more of a staging role when it is performed in a patient with a Stage II tumor who has not undergone sentinel lymphadenectomy. A modified dissection, which spares the sternocleidomastoid muscle, internal jugular vein, and spinal accessory nerve, is often preferred. Radical neck dissection is typically performed only if these structures are involved with tumor or the surgeon is inexperienced and/or unfamiliar with the modified approach.

References
1. Fleming ID, Cooper JS, Henson DE, et al. AJCC Cancer Staging Manual. 5th ed. Philadelphia, Pa: Lippincott-Raven; 1997:163-170.
2. Medina JE, Canfield V. Malignant melanoma of the head and neck. In: Myers EN, Suen JY, eds. Cancer of the Head and Neck. 3rd ed. Philadelphia, Pa: WB Saunders Co; 1996:160-183.
3. O’Brien CJ, Fisher SR. Neck dissection and parotidectomy. In: Balch CM, Houghton AN, Sober AJ, et al, eds. Cutaneous Melanoma. 3rd ed. Saint Louis, Mo: Quality Medical Publishing, Inc; 1998:245-257.
4. Reintgen DS, Rapaport DP, Tanabe KK, et al. Lymphatic mapping and sentinel lymphadenectomy. In: Balch CM, Houghton AN, Sober AJ, et al, eds. Cutaneous Melanoma. 3rd ed. Saint Louis, Mo: Quality Medical Publishing, Inc; 1998:227-244.