A nail tumor is a lesion found under the nail plate. It is attached to the nail bed or matrix. Most tumor growths of the nail bed are benign, but some may be malignant. These need to be removed surgically. Benign and malignant tumors both affect the nail and cause a deformity.
The tumors could be myxoid cysts, pyogenic granulomas, glomus tumors, onychocytic matricoma, Bowen disease or squamous cell carcinoma, and malignant melanoma.
Myxoid cysts are actually called pseudocysts because they are not surrounded by a capsule. The cyst stems from the connective tissue on top of the last finger segment. It looks like a shiny papule at the edge of the nail. It is semi translucent and contains a sticky fluid that may be tinged with blood when expelled.
They are also known as myxoid pseudocyst, mucous cyst, digital ganglion cyst, and digital synovial cyst. Most are benign and can be treated by merely draining the fluid with a sterile needle. In severe cases, surgical intervention may be required. They tend to reoccur.
Pyogenic granulomas are slightly raised bumps caused due to excessive growth of capillaries. They cause a swelling of the surrounding tissue. They are about a quarter to three-forth inch in diameter and rise from the nail bed or the surrounding tissue. They may not be painful but tend to bleed very easily. The condition can affect anyone.
Most pyogenic granulomas are benign and will disappear after a while. They may also be surgically removed by the doctor by curettage or electrodesiccation. It is a good idea to get a biopsy of the tumor to ensure that it isn’t malignant. Pyogenic granulomas may regrow even after being removed.
Glomus tumors are mainly found in subungual locations or under the nail. They are essentially a malformation of the veins rather than a skin tumor. They have also been found on the fingertip or in the foot. They arise from the glomus body and can affect toes or fingernails. They are mostly benign, but due to their small size can be difficult to diagnose. A biopsy must be conducted when possible
The tumors are classified into solitary, multiple or congenital. Another form is called glomangioma. This is usually reported at birth and is seen as a plaque-like lesion on multiple digits. Initially painless, they may later become tender to touch. Glomangiomas are inherited through autosomal dominant pattern, which means half of the children of an affected parent are likely to get it. Treatment includes laser removal, injection of hypertonic saline or sclerotherapy.
Onychocytic Matricoma is a tumor of the nail matrix. It is usually seen as a dark line under the nail. It is accompanied by localized thickening of the nail plate and melanonychia. Melanonychia refers to the brownish black discolouration of the nail. The tumor is keratogenous, which means it is caused by excessive production of keratin.
Treatment of Onychocytic Matricoma begins with exploration of the tumor which is then sent for a biopsy to check if it is malignant. Excision of the tumor may be enough for a benign lesion. Further options will be explored for a malignant tumor.
Bowen Disease or Squamous Cell Carcinoma
Squamous cell carcinoma is a skin cancer that affects the epidermis due to abnormal, uncontrolled growth of the squamous cells. The chief cause of the condition is high exposure to ultraviolet light. Men are twice as likely to get it as compared to women. Besides the nails, it can affect any area of the body that is frequently exposed to the sun such as the face, hands, arms and legs. Rarely it may also affect the genitals and mucous membranes.
Bowen’s disease is restricted to the epidermis and has not usually gone into the deeper skin layers. It is called intraepidermal squamous cell carcinoma. Early detection and removal of the squamous cell carcinomas usually results in a complete cure. A biopsy is recommended. Surgery, radiation, electrosurgery, photodynamic therapy or laser treatment may be used. Prognosis is usually quite positive if the tumor is eliminated in time.
Melanoma is a type of skin cancer that affects melanin producing cells. Besides the skin, it can affect the eyes, nails and in rare cases the internal organs. It usually appears as a dark stripe on the nail. Commonly found on the great toe or the thumb, it may be present on any digit. Essentially it is the skin on the nail bed which develops the tumor.
Melanoma of the nail bed is also called subungal melanoma. It is called ungual melanoma when it originates from under the nail plate and periungual melanoma when it originates from the skin besides the nail plate.
Dark-skinned people are more likely to be afflicted by this disorder. The general age group affected is between 40 to 70 years. It is diagnosed with a biopsy. If found malignant, the melanoma nail tumor needs to be surgically removed.
Reviewed by Yolanda Smith, BPharm