At the right thumb of a 68-year-old female patient an onychodystrophia with yellow-black coloration was visible of the remaining nail of the radial side. On the ulnar side the nail was nearly completely removed and reddish till distinct greyish matrix of the nail with irregularity of the surface appeared. No Hutchinson sign was detectable. She was skin type I-II, more than 100 small, non suspicious nevi in clinic and dermoscopy. No history of a melanoma in her own history or her family (Imaging system: FotoFinder).

In dermoscopy different wide yellowish, brown, grey and black streak appeared on the radial part of the nail. No micro-Hutchinson-sign was detectable (FotoFinder, 20fold magnification).

At the ulnar part of the nail irregular whitish, reddish till dark brown pigmented matrix of the nail was visible in dermoscopy. A polymorphia with pin point, comma vessels, streak-like vessels was clearly visible. Also no micro-Hutchinson-sign was detectable here (FotoFinder, 20fold magnification).

Diagnosis based histopathology
Subungual melanoma (tumour thickness 1.04 mm, Clark-Level III) with onychomycosis

Remarks
The patient was treated locally and systemically with the diagnosis of onychomycosis by several colleagues for any length of time. Due to the progression of nail destruction the presentation occurred in my practice.

References
Ronger S, Touzet S, Ligeron C, Balme B, Viallard AM, Barrut D, Colin C, Thomas L (2002) Dermoscopic examination of nail pigmentation. Arch Dermatol 138: 1327-1333.