A rodent ulcer is an outdated name for a kind of skin cancer called basal cell carcinoma (BCC). It was called a rodent ulcer because this kind of cancer sometimes looks like a tiny rodent bite on the skin.

Basal cell carcinoma is so named because it develops in basal cells in the lower level of the epidermis, which is the top portion of the skin.

BCC is the most common kind of skin cancer. Almost 75 percent of all nonmelanoma skin cancers are BCCs.

There are different kinds of BCCs. Each type can look different and cause different symptoms. These types include:

  • morpheaform BCC, which is also known as sclerosing basal cell skin carcinoma
  • nodular BCC, which is the most common kind
  • pigmented BCC
  • superficial BCC

Similar to other types of skin cancer, BCC typically happens on skin that’s exposed to the sun. This includes parts of the face, upper body, and lower body, like the:

  • forehead
  • cheeks
  • ears
  • nose and lips
  • neck
  • shoulders
  • forearms
  • back
  • lower legs

It’s most common in middle-aged people and older adults. Having BCC in the past raises your risk of getting it again.

BCCs may happen because a basal skin cell gets a mutation in its DNA. The mutated cell then starts to divide into abnormal skin cells.

It’s not known for certain why this happens. The most common cause is thought to be ultraviolet (UV) radiation from the sun and tanning lamps.

Other risk factors of BCC include:

  • getting sunburns
  • having fair skin
  • being middle-aged or older
  • living in a sunny area
  • living in a high altitude area
  • radiation therapy
  • having a family history of skin cancer
  • taking immune-suppressing drugs
  • exposure to toxic metals like arsenic
  • having a rare genetic disease like Gorlin-Goltz syndrome

Different kinds of BCCs can look quite different. In some people, they might be mistaken for other skin conditions like eczema or psoriasis.

If you have BCC, you may have signs and symptoms, like:

  • a red or irritated spot or patch on the skin
  • a shiny bump or nodule that’s transparent, pink, red, white, brown, or black
  • a small pink growth that has raised, rolled edges
  • a spot or patch of skin that looks like an open sore
  • a scar or patch that’s flat and white or yellow in color
  • a sore or ulcer that doesn’t heal within 4 weeks
  • a sore that heals and then comes back
  • an open sore that oozes, bleeds, or crusts
  • an itchy or painful sore or red spot

Here are some images of BCCs to give you an idea of how to identify it.

BCCs typically stay where they begin and don’t spread to other parts of the body. However, you can have this cancer in more than one spot at a time.

Your doctor or oncologist will likely treat and remove the individual spots or ulcers caused by BCC.

The area will be numbed with an injection before the small surgery. You won’t feel pain but will likely be awake.

You may have treatment or a procedure, such as:

Your doctor may also prescribe medicated creams or ointments that you put on the spot or medications that you take by mouth.

In some cases, BCCs can be treated with a medicated cream that stops the spot from growing. These include:

  • 5-fluorouracil (Efudex, Carac, Fluoroplex, Tolak)
  • imiquimod (Aldara, Zyclara)

Oral chemotherapy drugs for BCC include:

  • vismodegib (Erivedge)
  • sonidegib (Odomzo)

After your doctor or dermatologist has removed the BCC, the area should heal in about 2 to 4 weeks.

You may need a follow-up treatment and more procedures for a larger ulcer or if your doctor is removing the spot in stages.

Your doctor may prescribe an oral antibiotic and an antibiotic gel to make sure the area doesn’t get infected as you recover.

If the BCC is larger or has been there longer, more treatment may be needed.

Some kinds of BCCs are more difficult to treat, and in rare cases, aggressive kinds can’t be treated.

The cancer may come back on the same area if some of the skin cells are left behind after the spot or ulcer is removed. You might also get a new BCC growth on a different area.

See a dermatologist right away if you notice any symptoms on your skin. Early detection and treatment of BCCs is important for the best results.

In most cases, this kind of skin cancer can be cured if treated early.

A rodent ulcer is an uncommon and outdated name for basal cell carcinoma (BCC), a type of skin cancer.

This common skin cancer has several types and causes small bumps or open sores on the skin.

The most common cause is UV radiation from the sun. In most cases, BCCs can be removed, and you’ll fully recover.