Dermoscopic Examination of Nail Pigmentation

Abstract

Background: Diagnosis of longitudinal melanonychia is usually difficult, and neither a single clinical criterion nor a combination of symptoms currently can be used to clearly distinguish malignant from benign bandlike pigmented nail lesions. Biopsy is painful and often leaves definitive dystrophic scars.Objectives: To describe and evaluate dermoscopic patterns associated with longitudinal nail pigmentation.Patients and Methods: A total of 148 unselected consecutive cases of longitudinal melanonychia were included over a period of 4 years (20 melanoma, 37 nevi, 16 druginduced nail pigmentation, 45 nail apparatus lentigo of various types, 8 ethnic-type nail pigmentation, and 22 subungual hemorrhages). All patients were recruited from the dermatology unit outpatient clinic of the Hô tel Dieu de Lyon. All cases were photographed in vivo under oil immersion (dermoscopy). Patterns were recorded prior to final pathologic diagnosis. An independent biostatistics unit performed statistical evaluation using 7 semiologic patterns.Results: Melanoma cases were significantly associated with a brown coloration of the background and the pres-

Dermoscopy Allows Better Management of Nail Pigmentation

“…From the findings of Ronger et al, 18 the practical value of dermoscopic examination of nail pigmentation is evident, especially for subungual hemorrhage, which is in our experience the most common pigmentation of the nail and worrisome for patients who are not able to remember any trauma. The presence of red to bluishblack blood spots on dermoscopy allows the clinician to make the correct diagnosis with confidence and to reassure the patient immediately.…”

“…For the moment, Ronger et al 18 provide some criteria, but these are, in our opinion, not standardized enough to make this distinction, especially when the melanonychia is associated with periungual pigmentation.…”

“…The article by Ronger et al 18 tation are assessed systematically to allow differentiation between nail melanoma and benign longitudinal melanonychia with a high degree of diagnostic accuracy. Melanoma was significantly associated with a brown background and the presence of longitudinal brown to black parallel lines with irregular coloration, spacing, or thickness and disruption of parallelism, whereas nail apparatus nevi exhibited regular parallel lines on a brown background.…”

Malignant Melanoma S3‐Guideline “Diagnosis, Therapy and Follow‐up of Melanoma”

“…Employment of dermoscopy facilitates differentiation between benign and malignant tumors when examining non-pigmented or scarcely pigmented lesions [40], or nail lesions [41], and dermoscopically accessible mucous membranes [42].…”

Dermoscopy: Where are we?

“…For instance, in 2002, a study on the use of dermoscopy for analysis of nail pigmentation was published [9] . Similar to a pigmented lesion, as a first step, one has to determine if the nail pigment is of melanocytic origin or not (bloody or fungal).…”