The importance of nail biopsies to diagnose melanoma

It’s important that dermatologists know how to perform nail biopsies so that they can diagnose melanoma early. Here’s why you shouldn’t ignore melanonychia.

As experts in hair, skin, and nails, an important feature of dermatology is diagnosing and managing cutaneous malignancies. Naturally, patients expect the expertise with which we evaluate cutaneous lesions to extend to the management of them. Despite patient and professional expectations, much data exists showing that nail melanoma carries higher morbidity and mortality than cutaneous melanoma. This is likely due to a reticence to biopsy and the resultant later stage at diagnosis.

One notable manuscript provides an important retrospective review of nail biopsies for longitudinal melanonychia, or discoloration. This was performed at their institution over a 22-year period. In it, the number needed to biopsy four patients in order to diagnose a nail malignancy was established.

There are, however, limitations to this study. This is due to its retrospective nature as well as selection bias. It would be interesting to note the number of patients presenting with melanonychia where the decision was made not to biopsy and the long-term outcome and follow-up of these patients, too. The take-home point of this study is nevertheless salient: evaluate nails critically and biopsy often.

Barriers to nail biopsy are multifactorial, including psychological barriers for the patient and technical barriers for the clinician. Numbers reveal that one-third of graduating third-year dermatology residents are lacking in competency in nail procedures once completing training. Of the over 150 dermatology programs in America, only a handful offer exposure to a dedicated nail clinic and teaching. These factors often lead to a watch-and-wait approach to pigmented bands of the nail unit. This is something we will not tolerate on analogous cutaneous lesions.

My advice? Seek out nail training experiences through speciality organizations, such as the Council for Nail Disorders or the AAD’s Annual Meeting and Summer Innovation Academy’s hands-on cadaver nail surgery course. This has been shown to durably increase participants’ competence in nail surgery. If one isn’t interested or able to perform nail procedures, it is crucial to seek out local colleagues who perform these technically-demanding procedures often in order to appropriately aid patients with concerning bands of melanonychia.

Book an appointment with Dr. Julia Baltz here.