What to Know About Unusual Growths on Your Skin (Skin Neoplasms)

Medically Reviewed by Debra Jaliman, MD on May 27, 2023
3 min read

It can be alarming to find a growth on your skin, but don’t worry. Most growths, known as skin neoplasms, are harmless. However, some can be cancerous or precancerous, so make sure you get them looked at by a doctor. Your doctor may know exactly what kind of skin growth you have just by looking at it, or they may need to do a simple biopsy.

Benign neoplasms are not cancerous. Whether they need to be treated or not depends on their type and your symptoms. There are many different types of benign skin neoplasms, but they come in three major forms.

Flat and slightly raised lesions. These skin neoplasms are either macular, which is flat, or slightly papular, which is raised. Some of the most common of these are:

Raised lesions. These skin neoplasms are raised bumps. Some common benign papular skin growths include: 

Lesions beneath the skin. These are located underneath the epidermis, the upper layer of the skin. These can be lipomas or cysts.

Malignant skin neoplasms are cancerous. Early detection and treatment is important since almost all skin cancers can be cured by complete excision. There are several types of malignant skin growths.

Basal cell carcinoma. About 60% of malignant skin neoplasms are basal cell carcinomas. Usually found on skin that was exposed to many years of sun, basal cell carcinomas are a slow-growing neoplasm that invades tissue but doesn't spread. While they can grow anywhere, they’re most often found on the face or other exposed areas.  

Squamous cell carcinoma. About 20% of malignant skin growths are squamous cell carcinomas. This type of neoplasm is often found in patients that were exposed to ultraviolet radiation, like tanning beds, or in people who have been treated with drugs to suppress their immune system. 

Squamous cell carcinoma doesn't usually spread to other areas. However, squamous cell carcinomas that are more likely to metastasize are:

  • Located on the lip or ear
  • Come back after treatment
  • Located at the site of a burn
  • Deeply invasive

Malignant melanoma. Only about 1% of skin cancers are malignant melanoma. However, they are responsible for over 60% of skin cancer deaths. Malignant melanoma often metastasizes to other places, and it doesn't respond well to treatment. Malignant melanoma is more common in areas that have been exposed to sunlight, but can occur anywhere. There are four types:

  • Superficially-spreading melanoma, which has a slowly spreading irregular outline.
  • Nodular melanoma, which looks like a shiny, black dome.
  • Lentigo maligna melanoma, which has one or more hard black nodules.
  • Acral lentiginous melanoma, which occurs on the palms of hands, under nails, on the soles of feet, and on moist surfaces that line body cavities.

Precancerous growths. Precancerous skin growths, also called actinic keratosis or solar keratosis, are growths that, if left untreated, may develop into squamous cell carcinoma. There is no way to know which growths will become cancerous. If they’re treated quickly enough, there’s no risk of cancer from them.

Bowen disease. Bowen disease is a rare precancerous disease that mostly affects older adults. Patients experience a red scaly patch that slowly grows over time. Sun exposure is also a risk factor. Even though it’s precancerous, the chance that it actually develops into cancer is less than 10% chance it will develop into cancer, and treatment is usually successful.

A skin neoplasm of uncertain behavior is a skin growth whose behavior can’t be predicted. This diagnosis is only reached after your doctor has conducted a biopsy and sent the sample to a pathologist for examination. There's no way to know whether it will develop into cancer or not.

Many of these growths are natural and harmless, but as discussed, they may be cancerous. It’s important that you get any suspicious skin growths looked at by a doctor ⁠— early detection can save your life.