Carcinoma is the most common category of cancer, and its appearance varies significantly depending on the type and where it develops. On the skin, carcinomas typically show up as unusual bumps, non-healing sores, or scaly patches that change over time. Internal carcinomas, like those in the breast or lungs, aren’t visible on the surface but can sometimes cause noticeable skin changes. Here’s what each major type looks like.
Basal Cell Carcinoma
Basal cell carcinoma is the most common skin cancer, and it often looks deceptively harmless. The classic sign is a shiny, skin-colored bump that appears somewhat translucent, as if you can see slightly through the surface. On lighter skin, this bump typically looks pearly white or pink. Tiny blood vessels may be visible on or near the bump, though these are harder to spot on darker skin tones.
Not all basal cell carcinomas look like bumps. Some appear as flat, white, waxy patches that resemble a scar, with no clearly defined border. Others show up as slightly raised, reddish patches that may itch or crust over. One hallmark feature is that these spots tend to bleed easily, scab over, and then reopen. A sore that repeatedly heals and returns in the same spot is a red flag. Basal cell carcinomas grow slowly and almost always appear on sun-exposed areas like the face, ears, scalp, and neck.
Squamous Cell Carcinoma
Squamous cell carcinoma has a rougher, more textured appearance than basal cell. It often looks like a firm, dome-shaped growth with a raised border and a crusty or scaly surface. Many people describe it as a patch of dry, rough skin that won’t go away, or a sore that breaks open and bleeds without healing.
The earliest form, called squamous cell carcinoma in situ, typically appears as a scaly, dry-looking patch of rough skin on areas that have had significant sun exposure over the years. As it progresses, it can take on several different appearances:
- A non-healing sore that may be surrounded by raised skin
- A growth that bleeds when it breaks open
- A rough, scaly spot on the lip that may feel painful or tender
- A horn-like projection growing out of the skin, sometimes rapidly
- A pigmented, thickened patch that feels rough to the touch
On darker skin, squamous cell carcinoma can appear as raised, rough patches that are darker than the surrounding area. This type of carcinoma is more aggressive than basal cell, so changes in size, texture, or bleeding are worth paying close attention to.
How Carcinoma Differs From Melanoma
If you’ve heard of the ABCDE rule for checking suspicious spots (Asymmetry, Border irregularity, Color variation, Diameter, Evolving), that checklist applies specifically to melanoma, not carcinoma. Basal cell and squamous cell carcinomas arise from different cell types in the skin and look quite different from melanoma. Melanomas tend to be dark, multicolored, and irregularly shaped. Carcinomas are more likely to appear as pale, pearly, or flesh-colored bumps, or as rough, scaly patches. The key warning sign shared across all skin cancers is change: any spot that grows, bleeds, crusts, or won’t heal deserves evaluation.
Merkel Cell Carcinoma
Merkel cell carcinoma is rare but fast-growing. It typically appears as a firm bump on the skin that is painless, grows quickly, and looks pink, purple, red-brown, or the same color as the surrounding skin. The bump is often asymmetrical, with two sides that don’t match. It most commonly shows up on the face, head, or neck, and because it looks relatively unremarkable at first, it’s often mistaken for a cyst or insect bite. The rapid growth is what sets it apart. A bump that doubles in size over weeks rather than months warrants prompt attention.
Breast Carcinoma
Most breast carcinomas aren’t visible from the outside. Ductal carcinoma in situ, the earliest form, stays contained within the milk ducts and typically produces no visible skin changes at all. It’s usually caught on a mammogram. Invasive breast carcinoma, which has spread into surrounding breast tissue, may cause a lump you can feel but still often doesn’t change the skin’s appearance.
The exception is inflammatory breast cancer, an aggressive form that produces dramatic visible changes. Cancer cells block the lymph vessels in the breast skin, which causes the breast to look red, swollen, and warm. The skin develops a dimpled, pitted texture resembling the surface of an orange. This characteristic look is called peau d’orange. The nipple may also become inverted, turning inward rather than pointing outward. Unlike other breast cancers, inflammatory breast cancer rarely forms a distinct lump, so these skin changes are often the first noticeable sign.
Internal Carcinomas
Carcinomas of the lungs, colon, pancreas, prostate, and other internal organs aren’t something you can see or feel from the outside in most cases. These tumors are identified through imaging and biopsy rather than visual inspection. On imaging, internal carcinomas often appear as irregular masses with poorly defined borders. Lung adenocarcinoma, for example, can show up as a hazy or solid spot on a CT scan, with the edges blending into surrounding tissue rather than forming a clean, round shape.
Under a microscope, internal carcinomas have a distinct architecture. Adenocarcinomas, the most common subtype affecting organs like the lungs, colon, and pancreas, form abnormal glandular structures. Pathologists look for disorganized clusters of cells invading surrounding tissue, surrounded by a characteristic loose, fibrous material that signals the tumor is actively growing outward. The difference between an early, contained carcinoma and one that has become invasive comes down to whether those cancer cells have broken through the tissue layer where they started and begun spreading into deeper structures.
What to Watch For
Carcinomas don’t follow a single visual pattern, but a few principles hold across types. On the skin, be suspicious of any growth that changes in size, bleeds without clear cause, develops a crusty or scaly surface, or fails to heal within a few weeks. Pearly or translucent bumps, persistent rough patches, and sores that keep reopening are the most common presentations. On the breast, look for skin dimpling, pitting, redness, swelling, or nipple changes. Internal carcinomas rarely produce visible signs until they’re more advanced, which is why screening tests like mammograms, colonoscopies, and CT scans exist for higher-risk individuals.
Color alone isn’t a reliable guide. Skin carcinomas can be pink, red, white, pearly, flesh-colored, purple, or darker than surrounding skin depending on your skin tone and the type of cancer. Texture and behavior matter more than color. A spot that keeps changing, bleeding, or growing is more concerning than one that simply looks unusual but stays the same over time.