Melanoma

A large share of patients who arrive at our office convinced they have melanoma do not have melanoma. They have basal cell carcinoma or squamous cell carcinoma. The words "skin cancer" on a pathology report understandably read as alarming, and the distinction between tumor types is rarely explained in the moment.

The distinction is substantial. Basal cell and squamous cell carcinoma arise from keratinocytes, the structural cells of the epidermis. Melanoma arises from melanocytes, the pigment-producing cells. Basal cell carcinoma almost never spreads to distant sites; squamous cell carcinoma spreads uncommonly; melanoma has a genuine capacity to spread, which is why it is staged and followed differently.

Look at your biopsy report. If it says basal cell carcinoma or squamous cell carcinoma, you do not have melanoma, and the treatment is typically a single-day procedure under local anesthesia with a cure rate up to 99 percent. If it says melanoma in situ or lentigo maligna, the cancer is confined to the epidermis and has not invaded deeper tissue. In that state it cannot spread, and it is highly curable. If it says invasive melanoma, the report will include a Breslow depth in millimeters, which drives everything that follows.

If you are unsure what your report says, bring it to your consultation. Dr. Lopez will read it with you and explain exactly what it means before discussing any treatment.

Melanoma develops from melanocytes, the cells responsible for producing pigment. It accounts for a small share of skin cancer diagnoses but the majority of skin cancer deaths, because of its ability to spread if it is not caught early. Detected early, it is highly treatable with surgery alone.

Melanoma can appear anywhere on the body, including skin that receives little sun: the soles, palms, under nails, and mucosal surfaces. It commonly presents as a new or changing mole. The ABCDE rule is a useful guide:

A for Asymmetry:

one half of the spot does not match the other.

B for Border:

irregular, ragged, notched, or blurred edges.

C for Color:

uneven color or multiple shades of brown, black, pink, red, white, or blue.

D for Diameter:

larger than 6 mm (about the size of a pencil eraser), though melanomas can be smaller.

E for Evolving:

changing in size, shape, or color over time.

The "ugly duckling" sign is equally useful: a spot that simply looks unlike your other moles deserves evaluation, even if it does not tick the ABCDE boxes. Any lesion that is changing, bleeding, or new in adulthood should be examined by a dermatologist.

Melanoma in situ means the abnormal melanocytes are confined to the epidermis and have not invaded the dermis below. Because spread requires access to blood and lymphatic vessels in the deeper layers, in-situ disease does not metastasize. Treatment is surgical removal, and the prognosis is excellent.

Lentigo maligna is a subtype of melanoma in situ that arises on chronically sun-damaged skin, most often on the face, ears, scalp, and neck of older adults. It presents as a slowly enlarging, irregularly pigmented patch that is easy to mistake for an age spot.

Lentigo maligna presents a specific surgical problem: its true extent routinely reaches well beyond what is visible, with atypical melanocytes extending subclinically into surrounding sun-damaged skin. Combined with its preference for the face, where tissue is limited and every millimeter matters cosmetically, this makes accurate margin assessment particularly valuable.

Dr. Lopez performs two surgical approaches for melanoma, chosen by what the pathology shows.

Wide local excision. For invasive melanoma, the standard treatment is wide local excision, removing the tumor site with a measured margin of surrounding normal skin, with the margin width determined by the Breslow depth on your biopsy report. Dr. Lopez performs wide local excision for appropriate melanoma cases.

Slow Mohs (staged excision with comprehensive margin assessment). For melanoma in situ and lentigo maligna, and less often for superficially invasive melanoma, Dr. Lopez performs staged excision with comprehensive peripheral and deep margin assessment. The tissue is processed as permanent paraffin sections rather than frozen sections, and immunostains are used to make individual melanocytes reliably visible at the margin. Because permanent processing takes time, the procedure is staged across more than one day, which is where the term "slow Mohs" comes from.

This distinction is worth understanding. Conventional same-day Mohs surgery uses frozen sections, which are excellent for basal cell and squamous cell carcinoma but far less reliable for identifying single atypical melanocytes against a background of sun-damaged skin. Permanent sections with immunostains address that limitation directly. The trade-off is time: melanoma cases are not completed in a single visit the way basal cell and squamous cell cases are.

Dr. Lopez performs approximately 100 slow Mohs procedures per year for melanoma in situ and select early invasive melanomas.

Beyond surgery. Deeper invasive melanomas may warrant additional staging, such as sentinel lymph node biopsy, and more advanced disease may call for immunotherapy, targeted therapy, or radiation. These are managed with surgical, medical, and radiation oncology colleagues; Dr. Lopez coordinates with your referring physician and the appropriate specialists so that care is not fragmented.

Dr. Lopez completed his Mohs micrographic surgery and dermatologic oncology fellowship at Mayo Clinic and has personally performed over 10,000 Mohs procedures for non-melanoma skin cancers, alongside approximately 100 slow Mohs procedures per year for melanoma in situ and select early invasive melanomas.

He accepts melanoma referrals from dermatologists, primary care physicians, plastic surgeons, oculoplastic surgeons, facial plastic surgeons, and oncologists across Tampa Bay, including Wesley Chapel and Land O' Lakes. Referring physicians can review case coordination details on the Mohs surgery page.

A history of melanoma raises the risk of a second primary melanoma, so ongoing full-skin surveillance with your dermatologist is an essential part of long-term care, not an optional add-on.