How Many Types of Skin Cancer Are There and What Are the Differences?

Breaking down the core types, how they differ, and what changes in symptoms, urgency, and treatment because of those differences is needed to make the information clearer, reduce confusion, and help people recognise when to seek medical advice early.

What are the main types?

There are two main categories of skin cancer: melanoma and non-melanoma skin cancer. Among non-melanoma, the most common types are basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). These are the names you will hear most often because they account for the majority of diagnoses.

There is also an important third bucket people often fold into “types,” even though it is not cancer yet. Actinic keratoses (AKs) are precancerous growths caused by sun exposure, and they can develop into SCC.

On top of that, there are rarer skin cancers, but most day-to-day decisions still come back to melanoma, BCC, SCC, and spotting early changes.

If you suspect that you have skin cancer, the best course of action would be to consult with an oncologist who specialises in skin cancer to determine what kind of skin cancer you have and what treatment would be most viable for your condition.

Differences between melanoma and non-melanoma

The simplest difference is where the cancer starts. Melanoma begins in melanocytes, the pigment-producing cells that influence skin colour. Non-melanoma skin cancers usually start in other skin cells, most often basal cells or squamous cells, near the surface of the skin.

The second difference is how these cancers tend to behave. Melanoma is less common, but it has a higher tendency to spread if it is not caught early, which is why doctors treat suspicious moles with urgency. Non-melanoma cancers are often slower-growing and highly treatable, but they can still cause serious local damage, especially on the face, scalp, and neck, where important structures sit close to the skin.

Basal cell carcinoma (BCC)

Basal cell carcinoma (BCC) is the most common type of skin cancer. It often appears as a flesh-coloured round growth, a pearl-like bump, or a pink patch on the skin. Some BCCs also look like a slightly transparent bump or a sore that will not heal, and they can bleed or feel tender.

BCC is strongly linked to years of sun exposure or indoor tanning, and it often shows up on the head, neck, and arms, although it can form anywhere. The key point is that BCC rarely spreads to distant parts of the body, but it can keep growing into deeper tissue if it is ignored. That is when treatment becomes more complex, so the practical difference is that BCC rewards early action.

Squamous cell carcinoma (SCC)

Squamous cell carcinoma (SCC) is the second most common type of skin cancer. It often looks like a red firm bump, a scaly patch, or a sore that heals and then re-opens. It can also look like an ulcerated, non-healing wound, and it may become painful as it changes.

SCC tends to form on skin that gets frequent sun exposure, including the rim of the ear, face, neck, arms, chest, and back. It can also occur in people with darker skin tones, sometimes on sun-protected areas, which is one reason “I don’t burn” is not a safe rule. SCC can spread, although this is still less common than with melanoma, and that is why doctors are more likely to talk about staging and lymph nodes for SCC than they are for most BCCs.

Actinic keratosis (AK)

An actinic keratosis (AK) is not skin cancer, but it is not something to ignore. AKs are precancerous changes in the skin that can turn into SCC. They often show up as dry, scaly patches or spots, and they usually appear on areas that see a lot of sun, such as the head, neck, hands, and forearms.

The reason AK matters is that it gives you a warning before cancer develops. Treating AK and reducing ongoing UV exposure can lower the chance of progression, and it also prompts a wider skin check for other sun damage. In real terms, AK is often the point where prevention stops being theory and becomes a plan with specific next steps.

Rare skin cancers

There are rarer skin cancers, and they matter because unusual growths still need proper evaluation. Examples include Merkel cell carcinoma (often fast-growing and on sun-exposed skin) and dermatofibrosarcoma protuberans (DFSP) (often slow-growing and arising deeper in the skin). These are not common, but they can be missed if someone assumes skin cancer only looks like a “classic” mole or scaly patch.

The key difference with rarer cancers is that they are not something you can reliably self-diagnose. They can mimic harmless lesions, and their timelines and treatment plans differ from BCC, SCC, and melanoma. If a lump or patch persists, changes, bleeds, or ulcerates, the useful rule is that persistence beats guesswork, because a biopsy gives a definite answer.

What the differences look like in daily life and why they matter

Across all types, three differences tend to matter most to patients: what it looks like, how quickly it changes, and how likely it is to spread. BCC may look pearly or like a sore that will not heal, SCC often looks scaly or ulcerated, and melanoma may look like a new or changing mole. The appearance alone can overlap, which is why doctors focus on pattern, history, and examination.

The second set of differences is what happens next after suspicion. Many non-melanoma cancers are treated with local procedures, and Mohs surgery is often used in areas like the face, scalp, and neck where tissue preservation matters. Melanoma discussions often include stage-related planning because spread risk shapes everything from surgery margins to further tests, and that is a real-world consequence of the “type” label.

Staging and grading

Staging describes how far a cancer has grown or spread, and it depends on the type. Cancer Research UK notes that most BCCs do not need staging because spread is very rare, unless the cancer is very large. SCC is more likely to be staged because SCC can spread, even though it is still uncommon.

It also helps to know that Stage 0 is called carcinoma in situ, which means the cells have started turning into cancer but have not spread into nearby tissue. Squamous cell carcinoma in situ is also called Bowen’s disease, and it may develop into SCC without treatment. Grading is different from staging and refers to how abnormal the cells look under a microscope, with grade 1 looking more like normal cells and grade 3 looking more abnormal.

Those seeking private skin cancer treatment should understand these distinctions because staging and grading can affect how urgently treatment is recommended, which treatment options are considered, and what the expected outlook may be.

Focus on the common types, and act on change

So, how many types of skin cancer are there? In day-to-day practice, most cases fall into BCC, SCC, or melanoma, with AK acting as a common pre-cancer warning sign. The differences come down to cell type, appearance, speed of change, and spread risk, which then affects staging and treatment choices.

If a spot persists, changes, bleeds, or fails to heal, the consequence of waiting is often a larger procedure and more uncertainty than you needed to face. A prompt assessment turns a worrying unknown into a clear plan, and that is the practical advantage of understanding the main types and their differences.

About Dr James Wilson

Dr James Wilson is a Central London-based consultant oncologist specialising in lung cancer and advanced radiotherapy. In his private practice, he provides timely diagnosis, clearly defined treatment strategies, and composed, pragmatic support in critical moments.