Skin cancer is one of the most prevalent cancers, with current estimates indicating that one in five Americans will develop skin cancer during their life. While they are quite common, some of them can be life-threatening when neglected, therefore it is crucial to regularly check for any irregularities in the skin.
Types of Skin Cancer
Depending on the skin cells in which the growth occurs, skin cancers are then grouped into two main categories: non-melanoma skin cancers (keratinocyte carcinoma), which forms in the basal, squamous, or Merkel cells of the skin, and melanoma, a type of cancer that develops in the cells that produce melanin (melanocytes).
Non-melanoma Skin Cancers
Non-melanoma skin cancers are a broader grouping of skin cancers that develop slowly in the upper layer of the skin. There are various types of non-melanoma skin cancers, but the following are some of the main types:
Keratinocyte carcinomas include non-melanoma skin cancers which derive from keratinocyte cells on the epidermis. These include:
Basal cell carcinoma (BCC)
Basal cell carcinoma is the most common type of skin cancer, which develops as an abnormal growth of the basal cells in the outermost layer of the skin. Different from melanoma, this type of cancer grows slowly and has a good prognosis when caught early.
This form of skin cancer usually occurs in areas of your body that are most exposed to the sun, such as the head, neck, and face. Some of the most common signs include:
- open sores
- red, scaly patches
- pink growths
- shiny bumps
- scars or growths with elevated, rolled edges, and indented center.
Squamous cell carcinoma (SCC)
Squamous cell carcinoma is the second most common form of skin cancer that occurs in the squamous cells in the skin’s middle and outer layers. It usually develops in sun-exposed areas of the skin such as the head, lips, ears, neck, chest, upper back, legs, arms, and hands. This type of skin cancer also develops slower than others, therefore it is easier to treat when detected early.
Some of the signs of SCC include:
- red, scaly skin patches that are rough and bleed easily
- open sores that don’t completely heal or reappear after healing
- raised wart-like bumps
- a growth with raised edges and an indented area that may itch and bleed.
Merkel cell carcinoma
Merkel cell carcinoma (neuroendocrine carcinoma of the skin) is a rare and aggressive type of non-melanoma skin cancer that grows rapidly. It begins in the hormone-producing Merkel cells right beneath the skin and in the hair follicles and usually emerges in the head, face, or neck. This form of skin cancer typically appears as a firm and painless bump in shades of red, blue, or purple.
Melanoma is a malignant skin cancer that begins with an out-of-control growth of melanocytes, the cells that produce the skin’s pigment, a process that consequently causes a tumor to form. It is considered one of the most dangerous forms of skin cancer since, if left untreated, it typically spreads to other organs. There are four main types of melanoma which I will discuss below.
Superficial spreading melanoma
Superficial spreading melanoma is one of the most common types of melanoma that tends to spread outward onto the surface of the skin. It can be raised or flat, usually with irregular and asymmetrical borders. Its color can vary and can be shades of red, blue, brown, black, grey or white.
Nodular melanoma is the second most common type of this skin cancer, which grows deep and much quicker onto the skin, therefore it is considered the most aggressive. It mainly appears on the skin as a firm bump or node that rises above its surface and is usually black, red, pink, or the color of the skin.
Lentigo maligna melanoma
This type of melanoma most often develops in people of older ages and appears as a large, flat patch with an irregular border and tan or brown color. It develops from lentigo maligna (a subtype of melanoma in situ), which stays on the skin’s surface until it starts growing vertically, deep in the skin and it becomes lentigo maligna melanoma.
Acral lentiginous melanoma
Acral lentiginous melanoma is another less common form of melanoma that usually develops in darker skin colors, in people of African, Asian, or Hispanic ancestries. This form of melanoma is characterized by a darker spot on the skin, and its surface can be smooth and grow bumpier as it progresses.
These were some of the main types of skin cancer to beware of. If you spot an unusual growth or sign of any of the above, make sure you consult with your dermatologist so you can determine the best course of action together. As you have already learned by now different skin growths can represent many different pathologies on the skin. This is why it is so important that you see a skin expert for your skin needs as dermatologists receive 12+ years of training to be able to differentiate and adequately assess your lesions. Make sure you never let a non-dermatologist cosmetically remove your brown or pink spots without first evaluating if those growths are benign or cancerous.