Nail Unit Melanoma

Nail unit melanoma often presents as a dark-colored band (called melanonychia) within the nail plate (early stages) or a red, brown or black growth in the nail bed, destroying the nail plate (advanced stages). The pigment discoloration can spill over onto surrounding nail fold tissues (termed Hutchinson’s sign). Compared to benign causes of nail pigmentation (melanonychia), the discoloration in melanoma tends to be wider, darker and more irregular.

Common signs and symptoms of nail unit melanoma include:

• Dark Bands or Streaks: Melanoma may cause the development of pigmented bands or streaks called melanonychia within the nail plate, typically appearing as brown, black, or blue-black discoloration. Oftentimes, this band is wider than 3 millimeters.
• Changes in Nail Shape: Nail unit melanoma may alter the shape, contour, or thickness of the nail, causing irregular or asymmetrical growth.
• Ulceration or Bleeding: Advanced melanoma may form a nodule that can lead to ulceration, crusting, or bleeding around the nail unit.
• Pain or Discomfort: In some cases, melanoma may cause pain, tenderness, or discomfort in the affected nail or surrounding tissues.

The exact cause of nail unit melanoma is unknown. Unlike in melanoma of the skin, sun damage and ultraviolet (UV) radiation do not appear to play a significant role. Trauma or injury may be a risk factor in some patients. Other factors like genetics, family history or pre-existing moles can play a role. While nail unit melanoma is not inherently more aggressive than melanoma on other parts of the skin, nail unit melanoma is oftentimes diagnosed at a later stage, resulting in a potentially worse prognosis.

The diagnosis of nail unit melanoma is typically made through a combination of medical history, physical examination, and often a skin biopsy. Unlike other types of cancer, you can see skin cancers. This makes it easier to detect them early. Skin cancer screening exams and self-exams at home help detect skin cancer earlier. If you notice a discoloration around your nail or a darkening band within the nail plate, it is best to check in with a board-certified dermatologist and skin cancer expert like Dr. Thomas Knackstedt.

Here’s how the process generally unfolds (ideally the following paragraphs are separated by arrows):

Medical History

The team at Apex Skin Center will inquire about your medical history, including any previous skin conditions, family history of skin cancer, and any symptoms or changes in the skin or nail.

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Physical Examination

Board-certified dermatologist Dr. Knackstedt will conduct a thorough examination of the skin, focusing on any suspicious lesions or growths including an examination of all nails. Dermoscopy, a tool that allows for the magnification of structures within a skin growth is used to aid in the diagnosis of melanoma and can help differentiate melanoma from benign, noncancerous moles and freckles of the nail unit.

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Nail Unit Biopsy

If Dr. Knackstedt suspects nail unit melanoma based on the physical examination and dermoscopy findings, a nail unit biopsy may be performed. During a nail unit biopsy, a small sample of tissue is removed from the suspicious lesion under local anesthesia (numbing) and sent to a laboratory for analysis. The tissue is examined under a microscope to confirm the presence of melanoma and to assess the cancer’s characteristics.

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Once the diagnosis of nail unit melanoma is confirmed, further evaluation may be necessary to determine the extent of the cancer and plan appropriate treatment. As a fellowship trained, board-certified Mohs surgeon and dermatology oncologist (cancer specialist), Dr. Thomas Knackstedt and the team at Apex Skin Center have significant expertise in the management of all types of skin cancer and nail cancers. Dr. Knackstedt has authored over twenty papers on melanoma and has co-authored one of the definitive book chapters on nail cancer surgery.