Presence Of Hair In Skin Lesion Does Not Make It Benign

Skin Lesions and Hair

The presence of one or more hairs in a pigmented skin lesion does not guarantee that it is benign, according to a report in the March Journal of the American Academy of Dermatology.

"The presence of hair in a pigmented lesion should not automatically mean that the lesion under investigation is benign," Dr. Ashfaq A. Marghoob from Memorial Sloan-Kettering Cancer Center, New York told Reuters Health. "One needs to evaluate the primary morphology of the lesion in question and base one's decision on that."

Dr. Marghoob and associates sought to dispel the myth of the "benign hair sign" by reporting 3 cases of melanocytic lesions that showed terminal hairs on clinical and dermoscopic evaluation, but in which the final diagnosis was invasive melanoma.

In all 3 cases, terminal hair shafts could be clearly seen to protrude from the tumor, the authors report. Nevertheless, clinical, dermoscopic, and histopathological examination confirmed the presence of invasive melanoma.

"This may be due to the fact that the melanoma arose on a hair-bearing surface or arose in association with a nevus with hair without causing destruction of the hair follicles," the investigators say.

"It is very common (70-80%) for congenital melanocytic lesions to have increased hair," Dr. Marghoob added. "Thus, if hair is present within a pigmented lesion it is most likely to be a congenital melanocytic nevus. However, the presence of hair does not exclude the presence of melanoma."