Mucosal melanoma is a rare and aggressive form of melanoma that develops from melanocytes in the mucous membranes of the body. It is very rare, accounting for only ~1-3% of all melanoma cases1. The areas where it is most commonly discovered include the nasal passages, mouth, throat, gastrointestinal tract, urinary tract, and genital areas.
Unlike cutaneous melanoma, it is not associated with exposure to the sun. Because it most often occurs in less visible parts of the body, mucosal melanoma is frequently diagnosed at later, more advanced stages which makes it much more challenging to treat.
Treatment typically involves specialized care which may include surgery, radiation therapy, immunotherapy, or an available clinical trial.
Mucosal melanoma arises from melanocytes located in mucous membranes, which are the moist linings found inside parts of the body such as the nose, mouth, throat, digestive tract, genitals, and urinary tract. These melanocytes, which are the same pigment producing cells found in the skin, behave differently in mucosal membranes compared to that of the skin.
Because of these biological differences, mucosal melanoma does not behave like typical cutaneous (skin) melanoma. It often grows in less visible areas, is harder to detect early, and responds differently to treatment. For many patients, this diagnosis can feel confusing or unexpected, especially because there is usually no connection to sun exposure.
Mucosal melanoma is rare, but its impact is significant because it is often noticed and diagnosed at a later stage.
Mucosal melanoma can develop anywhere mucous membranes are present, but the areas where it is most commonly found are:
Because these are not areas people typically examine closely on a regular basis, changes can go unnoticed for longer periods of time. Many people are diagnosed only after symptoms become disruptive or concerning.
Unlike most skin melanomas, mucosal melanoma is not caused by ultraviolet (UV) exposure. This means that common factors such as sun exposure, tanning beds, and sunburn history are generally not considered risks for this melanoma subtype.
The exact causes remain unclear and are still being studied. Researchers believe that mucosal melanoma develops due to genetic and molecular changes within melanocytes, but these changes occur differently than in UV-related melanoma. Interestingly, mucosal melanoma can occur in people of any skin tone and often without any known risk factors.
For patients, this can be particularly frustrating as many people did not “do anything wrong” that might cause it.
Symptoms often vary depending on where the mucosal melanoma is developing. Some people have no noticeable symptoms early on, which is a huge reason diagnosis is often delayed.
Possible symptoms to watch for with various parts of the body:
These symptoms are often general and can also be caused by many non-cancerous conditions, which is why they may not immediately be associated with mucosal melanoma. Regardless, any persistent, unexplained, or worsening symptoms that you notice should be evaluated by a healthcare professional.
Diagnosis of mucosal melanoma begins when a clinician conducts an exam and evaluates the symptoms and identifies an abnormal area. A biopsy is required to confirm the diagnosis.
Most biopsies are performed as outpatient procedures, often in a clinic setting. The exact process depends on the location of the lesion, but many biopsies are quick and require only local anesthesia.
If the diagnosis is confirmed, additional testing such as imaging scans may be used to determine the stage of the disease and whether it has spread to other parts of the body. This information is critical to guide treatment decisions.
Determining the right treatment depends on several factors, including the location of the lesion or tumor, its size, whether it has spread, and a person’s overall physical health.
Common approaches to treatment may include:
When mucosal melanoma is diagnosed early, outcomes can be significantly better than when it is found at a later stage. However, because it often develops in areas that are difficult to see and may cause subtle symptoms, it is frequently diagnosed much later than cutaneous melanoma, which can make it more challenging to treat. For this reason, the overall prognosis is generally more serious than for many early-stage cutaneous melanomas.
Several factors influence prognosis, including how early the cancer is detected, where it is located, whether it has spread, and how well it responds to treatment. Ongoing advances in immunotherapy and continued research are also improving the treatment options and outcomes for some patients.
Because mucosal melanoma can present with subtle symptoms, it is important to seek a medical evaluation if you encounter:
It is a good rule of thumb to trust your instincts. If something does not feel right, it is reasonable to ask for further evaluation to be sure.
Reviewed by: Jess Scales
Expertise: Associate Director, Rare Melanoma ResearchLast medically reviewed: January 2026
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