Nevus-associated melanomas: clinicopathologic features.

OBJECTIVES: The clinical significance of nevus-associated melanoma compared with de novo melanomas remains controversial. It has been suggested that nevus-associated melanomas have a higher Breslow thickness and therefore worse prognosis. Over a 10-year period, this study evaluated the incidence of nevus-associated melanoma and its prognostic significance related to clinicopathologic features. METHODS: Cross-sectional study from 1995 through 2004 in a dermatopathology referral center. With available data, we evaluated sex, primary location, histologic subtype, Breslow thickness, Clark level, presence of ulceration, associated lesion, and histologic subtype of the associated lesion. RESULTS: Of 135,653 pathologic records from skin biopsy specimens over a 10-year period, 1,190 melanoma records were selected. Nevus-associated melanomas corresponded to 390 (32.8%) melanomas, with thin melanomas having a nevus 1.52 times the association observed with thick melanomas (>1.01 mm; 95% confidence interval, 1.16-1.99; P < .001). Superficial spreading melanoma was the most frequent, while no lentigo maligna melanoma was associated with nevi. The median Breslow thickness of nevus-associated melanomas was lower than that of de novo melanomas. CONCLUSIONS: Nevus-associated melanomas, which represent one-third of the melanomas in southeast Brazil, are associated with intermittent sun exposure, superficial spreading melanomas, and lower Breslow thickness. This is one of the largest series describing nevus-associated melanomas in Latin America.

Inner gray halo, a novel dermoscopic feature for the diagnosis of pigmented actinic keratosis: clues for the differential diagnosis with lentigo maligna.

BACKGROUND: Pigmented actinic keratosis (PAK) is a frequent simulator of lentigo maligna (LM) on the face upon clinical and dermoscopic examination, leading to misdiagnosis and unnecessary excisions. LM and PAK share dermoscopic features, making it difficult to have a confident diagnosis of PAK only with current dermoscopic knowledge. OBJECTIVE: We sought to evaluate sensitivity, specificity, and interobserver reproducibility of a novel dermoscopic feature, inner gray halo (IGH), and establish its histopathological and confocal correlations. METHODS: Dermoscopists blinded to histopathological diagnosis evaluated 58 PAK and 21 LM for the presence of IGH and dermoscopy parameters. Areas exhibiting IGH were marked and imaged with reflectance confocal microscopy before sampling for histopathologic correlation. Reflectance confocal microscopy and transverse histologic sectioning were performed in 14 of 79 cases. RESULTS: IGH was present in 53 of 58 (94.1%) PAK and in 5 of 21 (23.8%) LM in our series (sensitivity 91.4%; specificity 71.4%; positive predictive value 89.8%). Interobserver agreement was excellent (Kappa 0.846). Through transverse and perpendicular histologic sections, a dermoscopic-histologic-confocal correlation of IGH was established. LIMITATIONS: A larger test set is needed to further validate the use of IGH in the differential diagnosis of PAK and facial pigmented lesions. CONCLUSION: IGH is a novel dermoscopic parameter useful for the differentiation of PAK from LM on the face.

The use of fluor-hydroxy pulse peel in actinic porokeratosis.

BACKGROUND: The use of Fluor-Hydroxy pulse peel (Drogaderma, Sao Paulo, Brazil) was reported by Katz to treat solar damage and actinic keratosis-associated lesions. OBJECTIVE: The objective was to use this combined treatment to produce therapeutic and cosmetic benefits in a patient with actinic porokeratosis. METHODS: A case of actinic disseminated porokeratosis was treated with a combination of a 70% glycolic peel and a 5% 5-fluorouracil solution (Drogaderma) every 2 weeks for 4 months. A biopsy was done before and after eight treatment pulses. RESULTS: Improvement in the appearance and texture of the treated areas and decreased dyskeratosis and epidermal atypia. CONCLUSION: The Fluor-Hydroxy pulse peel can be an effective alternative for the treatment of actinic porokeratosis.