Cancers that can affect the toes are basal cell carcinoma, squamous cell carcinoma and malignant melanoma, according to the American Podiatric Medical Association. Malignant melanoma often manifests on the feet or beneath the toenails.
Malignant melanoma can develop anywhere on the feet, but it often appears as a black or brown line through the toenail, explains Medical News Today. Of the four types of malignant melanoma, superficial spreading melanoma is the most common and the least likely to spread down through tissue to bone. Acral lentiginous melanoma often occurs around the big toe. Although it rarely occurs in melanoma cases, people with darker skin tones are more likely to develop it.
Melanoma unique to toenails are longitudinal melanyonychia and amelanotic, states Medical News Today. Both types cause a change in the nail plate and, if it lacks pigmentation, can be misdiagnosed as a relatively harmless condition such as an ingrown toenail, warts or ringworm.
Basal cell carcinoma occurs on the sun-exposed skin of the feet and toes, says the American Podiatric Medical Association. It is relatively harmless and easily treatable, appearing as white bumps or sores. Squamous cell carcinoma causes the skin to take on a scaly appearance. It doesn't usually spread. An individual can prevent toe and foot cancer by apply sunscreen to his feet when he goes outdoors.