Seborrheic Keratosis With Prominent Clear Cell Changes-A Rare But Important Diagnostic Variant.

Seborrheic keratoses, although exceedingly common, occasionally have morphologic similarities to other lesions that complicate a typically straightforward diagnosis. The authors present a case of a 69-year-old man with a left shoulder lesion that displayed characteristic clinical and microscopic features of seborrheic keratosis on biopsy. However, diffuse and prominent clear cells were also noted. These stained strongly with Periodic acid-Schiff and were diastase sensitive, suggestive of glycogen accumulation and possible trichilemmal differentiation. This case is presented to demonstrate a unique and striking example of clear cell change within a seborrheic keratosis and to briefly review the published literature on this finding, which is rarely reported and demands close examination to exclude more aggressive neoplasms.

Cutaneous inoculation of nontuberculous mycobacteria during professional tattooing: a case series and epidemiologic study.

BACKGROUND: The increase in popularity of tattoos has coincided with an increase in reports of cutaneous inoculation of nontuberculous (atypical) mycobacteria (NTM) during the tattooing process. We report 3 NTM infections in otherwise healthy persons who received tattoos, which prompted a multiagency epidemiologic investigation. METHODS: Tattoo artists involved were contacted and interviewed regarding practices, ink procurement and use, and other symptomatic clients. Additional patients were identified from their client lists with an Internet survey. RESULTS: Thirty-one cases of suspected or confirmed NTM inoculation from professional tattooing were uncovered, including 5 confirmed and 26 suspected cases. Clinical biopsy specimens from 3 confirmed infections grew Mycobacterium abscessus strains that were indistinguishable by pulsed-field gel electrophoresis testing. Another 2 skin specimens grew Mycobacterium chelonae, which also grew from a bottle of graywash ink obtained from the tattoo artist. CONCLUSIONS: The pathogenicity and antibiotic resistance patterns of certain NTM isolates highlight the importance of correct diagnosis and potential difficulty in treating infections. Enforcement of new standards for the regulation and use of tattoo inks should be considered.