Best Practices for Diagnosing Cancer in Nails


Looks can be deceiving

Dermatologists need an understanding of the underlying causes of nail symptoms in order to accurately treat conditions.  Patients may usually form these conditions from factors that are not a form of cancer cells.  Symptoms like inflammation, infections, drug side effects, and trauma are most common in nail issues, but not exclusively.  Consequently, knowing the signs of squamous or melanoma symptoms is important.  Dr. Rich explains some of these factors to help you discern cancerous symptoms from more regular forms of nail problems.   

Lifting of nail plate from nail bed

Doctors will often run into Onycholysis – the lifting of the nail plate from the nail bed.  Especially relevant is the number of nails affected. If there are multiple nails showing symptoms, it’s often a sign of more benign causes.  Single nail symptoms however, increase the chance that the lifting of the nail is due to a tumor.

Doctors looking to discern between benign or malignant conditions on lifted nails should simply cut back the nail.  Onycholitic nails are somewhat removed from nerves, so patients will feel less discomfort, and you will be able to see the tissue below.  Dr. Rich emphasizes you cannot properly diagnose more dangerous conditions unless there is a biopsy, which requires getting underneath the nail.

Another important indicator are specific digits where lifting occurs.  Dr. Rich explains.  “Unlike melanoma which usually involves the thumbs, the second and third digits correlated more with squamous cell cancer.” Also noting in a study from a Belgian hospital that “the two of the top four presenting features of squamous cell cancer (under nails), were onycholysis and oozing.”

And finally, Dr Rich cautions against cauterizing a red nail bed until after you have taken a biopsy.

Dark Lines On Nails

Longitudinal melanonychia (the dark lines that appear on nails) are potential signs of malignant tissue under the nail.  Patients with gray, brown or black bands in the nail plate, often times have the same benign causes as lifting.  Grey lines in nails usually point to non cancerous sources, while black and brown lines have a higher percentage chance of being malignant.  So black and brown lines indicate that the nail should be cut back and examined.  Patients with LM may simply have blood underneath the nail, but if the color change is from a growth, you’ll be glad you did a biopsy.

Doctors should check the pattern of lines within the pigmented bands.  Patients with lines of regular thickness, spacing and color tend to suggest benign lesions.  Patients with longitudinal lines with irregular width, color and spacing might be at higher risk of melanoma.

Bringing it all together

In conclusion, patients come in with a wide range of potential causes for their nail problems.  Dr Rich makes clear that getting underneath the nail to see what going on at the bed of the nail is crucial.  When coloration is suspect, make sure that you get a biopsy.  Doctors who learn the tell tale signs of cancer cells with diagnose more effectively and produce better patient outcomes.