Melanoma is the medical term given for cancer. Cancer that develops in the nail unit is known as subungual melanoma. Melanoma can also occur on the palms and even on the soles. Subungual melanoma is also known as nodular melanoma. Nail melanoma can affect either your thumbnail or toenail. Cancer that occurs on the nail matrix is subungual melanoma. In case it occurs on the nail plate it is called as ungual and if it occurs beside the nail plate it is periungual melanoma.
Risk Factors :
- It is very rare to get melanoma in your nail matrix. Less than 1% of melanoma occurs in the form of subungual and often it targets white people, although it may occur in black people also.
- People with deep pigment are prone to subungual melanoma.
- Subungual melanoma occurs in the age ranging from 40-70 years.
- Trauma or injury to the nail is definitely a risk factor for melanoma.
Occurrence :
- As said already, subungual melanoma is a rare phenomenon.
- About 1-3% of people affected with melanoma can get subungual melanoma.
Subungual Melanoma Causes :
Cancers like nodular melanoma and desmoplastic melanoma can cause subungual melanoma. In some cases acral lentiginous melanoma can also affect nail matrix. In rare cases, hard blow or trauma to the nail can cause subungual melanoma.
Symptoms Of Subungual Melanoma :
- A band of pigments slowly appears on the nail plate. It does not happen overnight but is a gradual process. It may take several weeks or even months for the changes to get noticed. The pigment band becomes wide on the endings (cuticle) and is often irregular in pattern. The color of the pigment band can be in varying degrees of brown.
- After some weeks, the pigment band can progress to adjacent nail fold. In some cases the nodule may start bleeding appearing like ulcerous growth.
- Nails can crack in specific points and for some people nail can become thin and for others the nail gets distorted moving away from the nail plate.
- Often, subungual melanoma does not cause pain. In very rare cases if the tumor spreads to the underlying tissues and bones it can be painful.
Diagnosis :
If there is any changing pattern of the toenail or thumbnail you need to check with your health care provider. Pigment band measuring more than 3mm in length can be subungual melanoma. Dermatologist can examine the nail with special device to observe color changes, expansion of the width and space changes. The lines of band pigment will not run parallel to one other like normal nailing pattern. If the doctor is doubtful of the diagnosis, he may order for biopsy of the affected nail matrix. A small tissue sample is collected and tested in the lab for the presence of cancerous cells. The pathologist would also clarify whether the melanoma is invasive or in-situ.
Subungual Melanoma Treatment :
Local excision of the affected nail-bed is done if the melanoma is less than 1mm in breadth. Subungual melanoma is often removed by cutting off the entire nail matrix. In severe cases if the melanoma has spread intensely, the toe or affected finger is also removed. In rare cases the cancer would have spread to the nearby lymph nodes also and treatment is done as per the severity of the stage of cancer. Chemo and radiation are considered as last option if the cancer has metastasized to other areas.
Prognosis :
Patients with subungual melanoma where the cancer has not metastasized can live long. In this case since only the nail is affected and no other symptoms are present, often it gets delayed to diagnose it and get it treated. By then, the cancerous cells could have spread to the bones underneath and also to the nearby lymph nodes. Survival rates depend on the extent of spreading of cells and how far it has affected. Hence prognosis is poor in such cases.