Eruptive dermatosis papulosa nigra as a possible sign of internal malignancy.

A 42-year-old black woman presented with dermatosis papulosa nigra lesions of 15 years' duration. Coincident with the diagnosis of symptomatic iron-deficiency anemia about 1 year ago, she reported an "explosion" in number and size of the lesions progressing from her face to her trunk and arms. Physical examination revealed numerous 1-5-mm, black, smooth, verrucous papules predominantly on the forehead, malar region of the face, neck, and upper trunk (Figs 1 and 2). The lesions on the back were situated in a "Christmas tree" pattern and included two 1-cm papules. She had multiple 1-mm papules on the upper arms. A biopsy confirmed the diagnosis of dermatosis papulosa nigra, showing parakeratosis, acanthosis, hyperpigmentation, thick interwoven tracts of epithelial cells, and horn cysts. Given the eruptive nature of her disease, the possibility of an underlying malignancy was entertained. Six weeks later, she went to the emergency room for severe weakness; a colonoscopy revealed an ascending colon adenocarcinoma with a negative metastatic work-up.

Accuracy and predictors of basal cell carcinoma diagnosis.

BACKGROUND: Basal cell carcinoma (BCC) is the most common cancer in the United States. Therefore, prospective assessment of dermatologists' acumen in diagnosing BCC is important but, unfortunately, is lacking. OBJECTIVE. We sought to determine the positive predictive value (PPV) for clinically diagnosing BCC based on how confident the physician is of the diagnosis. We also sought to determine which clinical and historical factors most influence a dermatologist's perception that a tumor is a BCC and to determine which factors are correlated with a lesion being a BCC. METHODS: Dermatology attending faculty at the University of Miami performing biopsies on their patients in whom BCC was a consideration were asked to complete a questionnaire. They recorded how confident they were of their clinical diagnosis of BCC. They also recorded various clinical and historical factors about the patients and the lesions biopsied. RESULTS: The PPV for clinically diagnosing BCC when the clinician was most confident was 80%. Age (> 64 years) and the presence of pigmentation, telangiectasias, and a pearly border were statistically associated with a greater confidence level and a histologic diagnosis of BCC. Sunscreen use was associated with fewer diagnoses of BCCs. CONCLUSION: This is the first study to determine a relevant PPV for the clinical diagnosis of BCC because the PPV was based on clinical confidence level. These results highlight the role of diagnostic biopsies, could improve patient referral, and may help increase the PPV in the future.