Stage 4 skin cancer doesn’t have one single appearance. It means the cancer has spread beyond the original skin site to distant lymph nodes, distant skin, or internal organs like the lungs, liver, or brain. What you see on the skin depends on the type of skin cancer, how the original spot has changed, and whether new growths have appeared elsewhere on the body. The visible signs on the skin are only part of the picture, because much of what defines stage 4 is happening inside the body.
The Original Skin Lesion at Stage 4
By the time melanoma reaches stage 4, the primary tumor on the skin is typically thick, often measuring more than 4 millimeters deep. Tumor thickness is the single most important risk factor for spread. Thicker tumors are more likely to have irregular, uneven borders and multiple colors within the same spot, including shades of brown, black, red, white, or blue. The surface may look raised or dome-shaped rather than flat.
Ulceration is common in advanced melanoma. This means the skin covering the tumor has broken down, creating an open sore that may bleed, weep, or crust over. Sometimes the break in the skin is so small it can only be seen under a microscope, but in many advanced cases the ulceration is visible to the naked eye. The spot may look like a wound that refuses to heal.
For squamous cell carcinoma, an advanced tumor can appear as a firm nodule, a scaly red patch, or a raised sore with a crusted surface. These lesions tend to grow larger and deeper over time, sometimes eroding into surrounding tissue. Metastatic basal cell carcinoma is rare, but when it does spread, the original lesion has usually been growing and destroying nearby tissue for a long time, sometimes creating a deep, crater-like ulcer.
New Growths Away From the Original Spot
One of the most telling visible signs of stage 4 skin cancer is the appearance of new lumps or nodules on the skin that are separate from the original tumor. When melanoma or another skin cancer spreads through the bloodstream and lands in a distant skin site, it most commonly shows up as a firm nodule sitting in or just under the skin. In clinical studies, roughly 81% of skin metastases present as these nodular lesions. They can be skin-colored, pink, red-brown, or purple, and they range from small pea-sized bumps to lumps several centimeters across.
These new nodules can appear anywhere on the body, not just near the original cancer. They’re typically firm to the touch, painless at first, and may grow quickly. Some develop an ulcerated surface. Under magnification, doctors often see disorganized, irregular blood vessel patterns on the surface of these growths, along with structureless pink or whitish areas that correspond to dense clusters of tumor cells beneath the skin.
Swollen Lymph Nodes You Can Feel
Stage 4 skin cancer has, by definition, spread to distant parts of the body. One of the earliest visible or palpable signs of that spread is swollen lymph nodes. If the cancer has reached your lymph nodes, they can feel hard or swollen under the skin. The easiest places to notice this are the groin, armpits, and neck, where lymph nodes sit close to the surface. A swollen lymph node from cancer tends to feel firm and fixed in place, unlike the soft, movable swelling you might feel during a common infection.
Signs the Cancer Has Spread Internally
Much of what makes skin cancer “stage 4” isn’t visible on the skin at all. The cancer may have traveled to the lungs, liver, bones, or brain. When melanoma spreads to the brain, it receives its own separate classification in the staging system because of how significantly it affects treatment and outlook.
Internal spread produces symptoms that depend on which organs are involved. Lung metastases can cause persistent cough or shortness of breath. Liver involvement may cause pain in the upper right abdomen or yellowing of the skin. Brain metastases can lead to headaches, seizures, or changes in vision and balance. Bone metastases often cause deep, aching pain. General symptoms like unexplained weight loss, fatigue, and loss of appetite are also common as the disease advances.
Because internal spread can’t be seen from the outside, doctors rely on imaging to map the full extent of stage 4 disease. PET scans are especially useful for advanced melanoma, highlighting areas of high cancer activity throughout the body. CT scans show whether lymph nodes are enlarged or if organs like the lungs and liver contain suspicious spots. MRI is the preferred tool for evaluating spread to the brain and spinal cord. Many cancer centers now use combined PET/CT machines that overlay metabolic activity onto detailed anatomical images.
How Stage 4 Is Different From Earlier Stages
Earlier stages of skin cancer are defined by what’s happening at the original site. Stage 1 melanoma, for example, is 1 millimeter thick or less. Stage 2 tumors are thicker, potentially with ulceration, but still confined to the skin. Stage 3 means the cancer has reached nearby lymph nodes or has produced satellite lesions close to the primary tumor. Stage 4 is the point at which cancer has reached distant organs or distant skin sites, regardless of what the original tumor looks like.
This is an important distinction: a small, thin-looking mole on the skin doesn’t rule out stage 4. The original spot might even have been surgically removed months or years earlier. Stage 4 is determined by where the cancer has traveled, not by the size or appearance of where it started. That said, the five-year survival rate for stage 4 (distant) melanoma is about 16%, which is significantly lower than earlier stages. Advances in immunotherapy have improved outcomes for many patients in recent years, but the stage still carries serious implications.
What to Actually Look For
If you’re examining a spot on your skin or someone else’s and wondering whether it could be advanced, the key warning signs include a mole or growth that has become noticeably larger, darker, or more irregular in shape over time. Multiple colors within the same lesion, an open sore that bleeds or crusts and won’t heal, and a spot that has become raised or dome-shaped are all concerning features. Any new firm lump under the skin, especially one that appears away from an existing or previously treated skin cancer, warrants prompt evaluation.
Hard, swollen lumps in the neck, armpits, or groin that persist for more than a few weeks are another signal, particularly in someone with a history of skin cancer. Unexplained weight loss, persistent pain in the bones or abdomen, and new neurological symptoms like headaches or vision changes alongside a known or suspected skin cancer can point toward distant spread.