Melanoma, also called malignant melanoma, arises in the pigment producing cells of the skin called melanocytes. It is much less common than basal cell or squamous cell carcinoma, but it can also be much more serious. When caught early, it can be easily cured with surgery.
The longer melanoma is present, the more likely it is to metastasize, or spread, to other parts of the body including adjacent lymph nodes or even more distant areas. Melanoma usually appears as an irregularly shaped mole on the skin and can appear anywhere, not just on sun exposed areas. Since it arises from melanocytes it is usually composed of shades of black or brown, but may also contain shades of red and blue. There are several subtypes of melanoma. These include melanoma-in-situ, which is confined to the very top layer of skin and is almost always curable by surgically removing it, as well as superficial spreading, nodular, lentigo maligna, and acral lentiginous melanomas.
The thickness of amelanoma(how deep it extends under the skin) is very important, as this affects the prognosis and treatment. The thickness is measured in millimeters. The thicker the melanoma, the more likely it is to have spread to other parts of the body. A thin melanoma is less than or equal to 0.8mm, and these melanomas are almost always treated exclusively with surgery under local anesthesia in our offices. This surgery may be either a standard excision, or Mohs surgery. An intermediate melanoma is 0.8 mm to 4 mm thick and is typically treated with surgery in addition to a ‘sentinel lymph node biopsy’. A sentinel lymph node biopsy is performed by a surgical oncologist, and he or she will inject a dye into the area of the cancer to see which lymph nodes the tumor drains to. These lymph nodes are then sampled to make sure that the melanoma has not spread to the lymph nodes. Sometimes patients with intermediate melanomas receive systemic treatment in addition to surgery and sentinel lymph node biopsies.
Thick melanomas are greater than 4 mm, and imaging studies are almost always done to ensure that the melanoma has not spread to other parts of the body. Treatment of these thicker melanomas often involves systemic therapies through medical oncologists, in addition to surgery.
Not too long ago, there were limited effective treatments for aggressive melanomas or melanomas that had metastasized to other parts of the body and the prognosis was very poor. However, in the last few years a new type of treatment called immunotherapy has vastly improved our ability to treat and even cure more aggressive melanoma. The immunotherapy medications are intravenous infusions that stimulate the body’s own immune system to attack the cancer cells. There are several immunotherapies approved for melanoma including pembrolizumab (Keytruda), nivolumab (Opdivo), atezolizumab (Tecentriq), and ipilimumab (Yervoy). In addition to these immunotherapies, there are other targeted systemic agents that are used to treat aggressive melanoma including BRAF inhibitors (vemurafenib, dabrafenib, and encorafenib) and MEK inhibitors (trametinib, cobimetinib, and binimetinib).
If you do have a deeper melanoma that requires a sentinel lymph node biopsy or systemic treatment, we will refer you to a center specializing in the treatment of melanoma where a comprehensive evaluation and more advanced treatments can be provided. As always, even if we refer you to a specialty center, we will be available to answer any questions that may arise and to guide you throughout the process.
If you or a first-degree relative have had a melanoma, you should be screened regularly with a full body skin examination by a dermatologist to monitor for a recurrent or new melanoma. After a melanoma diagnosis, these skin examinations are typically done every 3-6 months for several years and then may be spaced out. You should also perform self-exams to look for suspicious growths on your skin, and let us know if you have noticed any new lesions in between your scheduled skin examinations.