MONTEREY, CALIF. The initial preoperative diagnoses of nail lesions that prove to be squamous cell carcinoma run the gamut from onychomycosis to subungual verruca, Dr. Phoebe Rich said at the annual meeting of the California Society of Dermatology and Dermatologic Surgery.
In her own practice, one such lesion was oozing and appeared onycholytic, she explained, displaying a slide of the crusty lesion at the nail edge.
"It doesn't look like much," said Dr. Rich, director of the nail center at Oregon Health and Science University, Portland.
Among 13 SCC cases diagnosed by Dr. Rich, who is also in private practice, six appeared verrucous and six eczematoid, in addition to the onycholytic case.
Earlier this year, a clinicopathological review of SCC of the nail apparatus by French researchers revealed that subungual SCC was the preoperative diagnosis in only 10 of 35 patients (Br. J. Dermatol. 2007;156:871-4). Nine cases were originally thought to be onychomycosis, five were diagnosed as subungual verruca, and five were thought to be "longitudinal melanonychia (nevus, melanoma)." Six cases carried a variety of other preoperative diagnoses, including exostosis and onychomatricoma.
The lesson is to always be thinking of SCC of the nail as a possibility, she stressed.