Nail clipping histopathology first step in detecting nail unit melanoma

February 17, 2023 | Histopathology

Melanonychia, the dark discoloration of the nail, poses a challenge to clinicians as it often appears to be benign but can be cancerous. Current definitive diagnosis for melanonychia commonly requires nail matrix sampling but this method causes discomfort and permanent nail dystrophy to the patient.

According to Journal of Cutaneous Pathology, dermatologists and dermatopathologists should increase use for nail clipping histopathology in the diagnosis of nail unit melanoma. Adam I. Rubin, MD, associate professor of dermatology, pathology, laboratory medicine and pediatrics at Penn Medicine stated that patients resistant to a soft tissue nail biopsy are more willing to have their nail clipped. However, it was specified that the clinicians must require a sample that is 4 mm in length, as smaller samples may not be representative.

According to Rubin and colleagues, the presence of melanocyte remnants or pieces of pigment-producing cells from the examined nail clippings are diagnostic signs for nail unit melanoma. Furthermore, the longitudinal density and dorsal location of these melanocyte remnants offer the greatest indication for melanoma.

Nail clipping histopathology can also assist in the diagnosis of other nail conditions such as nail psoriasis, onychomatricoma and subungual hematoma.

Thus, nail clipping histopathology serves as an attractive first line of diagnosis with its ability to rapidly determine nail unit melanoma with minimal invasion. With this method, important patient care can be expedited and clinicians’ time will be used more efficiently. Authors believe that there is enough evidence for all clinicians to consider this change in routine and practice.