Nail clipping histopathology recommended first step in diagnosing nail conditions, cancer

Dermatologists and dermatopathologists should increase the utilization of nail clipping histopathology to aid in the diagnosis of nail unit melanoma, according to a perspective published in the Journal of Cutaneous Pathology.

The diagnosis and management of melanonychia — dark discoloring of the nail — can be challenging for clinicians as it is often benign but can be cancerous. According to the perspective authors, definitive diagnosis typically requires nail matrix sampling; however, this method can cause patient discomfort and permanent nail dystrophy.

“Patients resistant to a soft tissue nail biopsy are more willing to have their nail clipped and examined, and that alone can help determine whether an urgent intervention is needed,” Adam I. Rubin, MD, associate professor of dermatology, pathology and laboratory medicine and pediatrics at Penn Medicine and one of the perspective authors, said in a press release.

Therefore, nail clipping histopathology poses as an appealing first line of diagnosis with its ability to rapidly indicate nail unit melanoma with minimal invasion.

According to Rubin and colleagues, nail clippings examined with a microscope may demonstrate pieces of pigment-producing cells called melanocyte remnants. The presence of these remnants is recognized as a diagnostic sign for nail unit melanoma. Even more so, the longitudinal density and dorsal location of melanocyte remnants provide the greatest indication of nail unit melanoma.

Utilizing nail clipping histopathology can also aid in the diagnosis of other nail conditions such as nail unit psoriasis, onychomatricoma and subungual hematoma, according to the perspective.

However, the perspective authors specified clinicians must allow for a sample that is 4 mm in length, as smaller samples may not be representative.

“If clinicians use this as a first step in diagnosing nail conditions and cancers, important patient care can be expedited and clinicians’ time will be used most efficiently,” Rubin said. “We believe there is now enough evidence for all clinicians to make this change in routine practice and advance patient care.”

Reference:

• Penn researchers find nail clippings can signal potential melanoma in fingernails, toenails. Published Jan. 23, 2023.