Four ways to treat melanoma

The tumor originates from the neural crest of the ectoderm. Melanocytes are located between the epidermis and basal cells. After the cells produce pigments, they transport melanin particles to basal cells and hair through dendrites. Most malignant melanomas occur due to repeated friction, scratching and damage to melanin nevi. Improper excavation and drug corrosion can transform benign melanin nevi into malignant melanomas. Malignant melanomas develop rapidly in women during pregnancy or childbearing age, indicating that the disease is related to endocrine.

Four approaches to surgical treatment of melanoma

1. Biopsy

For patients suspected of malignant melanoma, the lesion should be removed in one piece together with the surrounding 0.5cm to 1cm of normal skin and subcutaneous fat for pathological examination. If it is confirmed to be malignant melanoma, the depth of infiltration will determine whether additional extensive excision is needed. Generally, incisional or forceps biopsy is not performed unless the lesion has ulcerated or the lesion is too large and a single excision will cause disfigurement or disability and must be confirmed by pathology first. However, the incisional biopsy must be connected to radical surgery as close as possible. In a prospective analysis, the World Health Organization Collaborating Center for Diagnosis and Treatment Evaluation of Malignant Melanoma believes that excisional biopsy not only has no adverse effect on prognosis, but also can understand the depth and range of infiltration of the lesion through biopsy, which is conducive to formulating a more reasonable and appropriate surgical plan.

2. Extent of resection of primary lesion

The old view that 5 cm of normal skin must be included when resecting the lesion has been abandoned. Most tumor surgeons only remove 1 cm of normal skin outside the tumor edge for thin lesions with a thickness of ≤1 mm, and perform wide resection 3 cm to 5 cm from the tumor edge for lesions thicker than 1 mm. Malignant melanoma located at the extremities often requires finger (toe) amputation.

3. Regional lymph node dissection

1. Indications

For patients with lesion thickness ≤1mm, the metastasis rate is very low, and preventive lymph node dissection cannot be expected to change the long-term prognosis; for patients with lesion thickness >3.5cm-4mm, the possibility of occult distant metastasis is high, and the long-term survival rate is relatively low (20%-30%). Even if preventive lymph node dissection is performed, it is difficult to expect a significant improvement in survival rate. Despite this, there are many people who advocate that preventive lymph node dissection should be performed as long as there are no distant metastatic lesions to be found; for lesions with thickness between the above two categories, the occult lymph node metastasis rate is quite high, and preventive lymph node dissection is the best candidate for improving survival.

2. Scope of regional lymph node removal

When performing cervical lymph node dissection for malignant melanoma of the head and neck, if the primary lesion is located on the face, the lymph nodes in the parotid area, submental area, and submandibular triangle should be removed; if the lesion is located in the occipital region, the lymph nodes in the posterior cervical triangle should be removed. Malignant melanoma occurring in the upper limbs requires axillary lymph node dissection, and those occurring in the lower limbs should undergo inguinal or ilioinguinal lymph node dissection. Malignant melanoma occurring in the chest and abdomen requires ipsilateral axillary or inguinal lymph node dissection, respectively.

4. Palliative resection

For patients with large lesions and distant metastases who are not suitable for radical surgery, debulking or palliative resection may be considered to relieve ulcer bleeding or pain, as long as anatomical conditions permit.