The mainstay of treatment is early diagnosis and excision. A suspicious lesion is any pigmented lesion that is asymmetrical, has border irregularity, color change, and diameter greater than 6 mm (the ABCD's of malignancy). The presence of red, white or blue variegation in a brown or black lesion is highly suspicious. Any rapidly changing or ulcerating lesion is highly suspicious for melanoma.
Whenever possible, suspicious lesions should undergo complete excisional biopsy with a 1-2 mm rim of normal skin in an elliptical shape. If the lesion is large (over 1.5 cm), or in a location where skin removal is critical, an incisional biopsy (punch biopsy) should be taken from the most raised or irregular area. If incisional biopsy is used for diagnosis, the management should not be based on the Breslow depth because there may be thicker areas that were not sampled. The biopsy is carried down to normal subcutaneous fat, but not through the underlying muscle fascia.
Biopsy can be done in the clinic with local anesthetic (a mixture of 1% lidocaine with 1:100,000 epinephrine, and an equal volume of 0.5% Bupivicaine). One must consider the relaxed skin tension lines and orientation as future wide local excision may be needed. The specimen is handled carefully and sent to the pathologist according to hospital protocol. The skin is closed with care, in layers if necessary, as frequently no more surgery will be required (if the lesion is benign). Subungual lesions are biopsied by removing the nail and performing an excisional biopsy down to, but not including periosteum.
Once the diagnosis of melanoma is made, definitive surgical treatment should be scheduled as expeditiously as possible. The surgical plan is based on the histopathologic depth of the tumor (Breslow depth). For incisional biopsies, one must ensure that the plan is based on the deepest part of the tumor, which may not have been the part first incised. The lesion is staged based on the depth of invasion and the presence of palpable nodes on exam.
Tumors can then be categorized into thin tumors (<1 mm thick) amenable to wide local excision only down to the muscle fascia, intermediate tumors (1-4 mm thick) that need sentinel lymph node biopsy and possibly total lymph node dissection, and thick tumors (>4 mm thick) that have likely metastasized at the time of diagnosis.
Wound closure is typically performed immediately after excision. Reconstruction should stick to the reconstructive ladder: primary closure when possible, skin grafts and flaps if primary closure is not possible. Complex defects with limited reconstructive options are generally treated with temporary dressings or skin grafts until permanent pathology sections confirm negative margins.
Patients with intermediate lesions 1-4 mm thick historically underwent elective lymph node dissection (ELND) with resulting morbidity. The role of sentinel node biopsy (SNB) would be to assess the local nodal basin for metastases with no morbidity and tariff of total lymph node dissection. Any patient with ulceration or regression, males with Clark level III or greater lesions, and patients with intermediate thickness tumors (1-4 mm) should undergo SNB.
The foundation for SNB is that nodal metastases follow an orderly progression and that the histology of the sentinel node reflects the whole nodal basin. Therefore, when the sentinel node is free of charge of disease, no further dissection is needed. If tumor is located, a therapeutic nodal dissection is conducted removing the entire nodal basin.
Palpable nodes (regardless of tumor depth) that are not suspicious can be evaluated with surveillance and fine needle aspiration (or open biopsy). Palpable nodes that are in the basin draining the main site, or are otherwise suspicious, should undergo elective lymph node dissection without biopsy.
For patients undergoing SNB, preoperative lymphoscintigraphy aids in localization of the tumor. The technique requires the intradermal injection of a radio-labeled colloid and dynamic imaging over a 2 hour period. This enables the surgeon to find the approximate part of the sentinel node and it is especially important for regions with irregular drainage (like the head and neck).
The individual should then learn from the risks of SNB, specifically the risk that the process may need to be transformed into a complete lymphadnectomy when the sentinel node is positive. Intraoperative vital blue dye lymphatic mapping (1-3 ml of lymphazurin blue dye injected to the dermis) can be an adjunct to intraoperative lymphoscintigraphy detection. Histologic examination is conducted on all excised lymph node using routine and immunoperoxidase S-100 and HMB-45 stains. Intraoperative frozen section isn't routinely performed.
Intraoperative complications include anaphylaxis, retained blue hue and inaccurate oxygen saturation readings. Cooperation between the radiologist (lymphoscintigraphy), surgeon (biopsy), and pathologist (histology) is essential to the success from the procedure and it has resulted in only a 4-11% false negative rate.
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