In 2010, an estimated 68,130 people will receive a diagnosis of cutaneous melanoma, and 8,700 will die from the disease.1 Twenty-five percent of melanoma lesions are located on the head and neck, a region that represents approximately 10% of the skin's surface area. Excessive sun exposure, including frequent sunburns at a young age, is a significant risk factor for developing the disease.2,3 Melanoma often arises in pigmented lesions. Patients presenting with melanoma of the head or neck commonly have the lesions on sun-exposed areas such as the vertex of the scalp, helix of the ear, nose, and neck. This review discusses the preoperative evaluation of a patient with cutaneous melanoma of the head and neck, the surgical management of melanoma, and adjuvant therapy available for this disease.
CASE REPORT
A 62-year-old male with a history of excess sun exposure presented with a raised, darkly pigmented lesion on the left posterior neck that had persisted for 2 months but had recently grown in size. A biopsy of the lesion revealed invasive melanoma. The patient was subsequently referred to our facility for evaluation. Review of the biopsy specimen demonstrated a Clark level IV lesion with Breslow thickness of 3 mm and mitotic rate of 9/mm2. Ulceration was not identified in the specimen. On physical examination, the patient had a 1-cm darkly pigmented macular lesion that was located on the left posterior neck just below the hairline (Figure 1). The border of the lesion was slightly irregular with no significant color variation. No palpable neck adenopathy was appreciated. The remainder of the physical examination was unremarkable.
Several diagnostic studies were performed. Lymphoscintigraphy, which uses routine serial static planar images (Figure 2) as well as fused single-photon emission computed tomography (SPECT)/CT of the head and neck (Figure 3), was performed after intradermal injection of 0.5 mCi of technetium-99m sulfur colloid around the lesion. The scintigram demonstrated drainage into the left parotid gland, left jugular nodes, and left upper posterior cervical lymphatic chains. The patient's chest radiograph and CT scans of the chest, abdomen, pelvis, and brain revealed no evidence of metastasis. The results of laboratory studies were all within normal limits.
After the findings and indications were reviewed, the patient agreed to have surgery. On the day of surgery, he received another intradermal injection of 0.5 mCi of technetium-99m sulfur colloid around the known lesion in the left posterior neck 1 hour prior to surgery. In the operating room (OR), the same site was infiltrated with 1 mL of isosulfan (Lymphazurin) blue dye (Figure 4). A wide local excision of the left posterior neck lesion was performed using 2-cm circumferential margins; then the specimen was sent for histologic analysis. Next, a gamma probe was utilized to perform sentinel lymph node mapping. Several nodes of the left parotid and left neck were detectable in vivo; subsequently, these nodes were excised and sent for pathological evaluation by multistep sectioning and immunohistochemistry. The final pathology revealed one positive left parotid node (out of five identified sentinel nodes) containing metastatic melanoma with the presence of extracapsular extension. The specimen from the wide local excision of the neck revealed no evidence of melanoma at the margins.
Since metastatic melanoma was present in the sentinel node, the patient returned to the OR 1 week later for a superficial parotidectomy, left neck dissection, and full-thickness skin graft of the primary site. Final pathological analysis revealed that 4 of 32 left neck nodes contained melanoma. Subsequently, the patient was scheduled to receive 30 Gy of postoperative radiation in 5 fractions over 2½ weeks to the left parotid bed and neck as well as IV interferon-alfa for 12 months.
DISCUSSION
When evaluating a patient who has a suspicious cutaneous lesion, the clinician should use the ABCDE melanoma evaluation algorithm to check the lesion for asymmetry, border irregularity, color variation, diameter greater that 6 mm, and evolution. The National Comprehensive Cancer Network practice guidelines advocate elliptical or punch biopsy to obtain pathological confirmation of the lesion.4 This allows for a complete assessment of the depth of invasion (Breslow thickness), the presence of ulceration, and the mitotic rate, which are all needed to accurately classify and stage the lesion.