No abstract

The predictive value of melanoma diagnosis made by visual examination during pigmented lesion screening is low. This creates the problem of false-positive diagnoses, which lead to unnecessary treatment and scarring. The purpose of this study was to evaluate the impact of dermoscopy (epiluminescence microscopy, dermatoscopy) on the false-positive rate in the routine melanoma screening activity of a pigmented lesion clinic (PLC). In a series of 133 subjects consecutively referred to the PLC, lesions defined as suspicious or equivocal on visual examination were examined by dermoscopy. Only lesions also defined as suspicious on dermoscopy were excised; other lesions were observed at follow-up examinations. Among the 2542 pigmented lesions observed, clinical examination led to identification of 43 suspicious lesions, 13 of which were also suspicious on dermoscopy and were subsequently excised. Histopathological examination revealed three malignant melanomas. Compared with visual examination alone, the addition of dermoscopy to the subgroup of clinically equivocal lesions resulted in an increase in specificity from 98.4% to 99.6% and in positive predictive value from 6.9% to 23%. The specificity of the visit outcome 'subject to be referred for surgical excision' increased from 69.2% to 92.3%. No false-negative melanoma diagnoses on dermoscopy were observed during a follow-up period of 4 years. The addition of dermoscopy to routine PLC activity as a second-level examination led to a reduction in the number of false-positive diagnoses, thus producing an overall increase in the specificity and positive predictive value of melanoma diagnosis.

The authors of the May 10, 2020 article entitled "Factors Affecting Sentinel Node Metastasis in Thin (T1) Cutaneous Melanomas: Development and External Validation of a Predictive Nomogram" (J Clin Oncol 10.1200/JCO.19.01902) have made errors in Figure 1 that affect the accuracy of the nomogram. Since this nomogram may have implications for patient care, JCO has decided to temporarily suspend online publication of this manuscript until this matter has been fully addressed. A corrected version of this manuscript will be made available as soon as possible.

The objective of this study was to evaluate the time trend of melanoma thickness in a population-based case series. All invasive (n=2862) and in-situ (n=605) cutaneous melanoma incident cases diagnosed in 1985-2004 were retrieved from the Tuscany Cancer Registry, central Italy. Standardized (European population) incidence rates were computed for four periods: 1985-1989, 1990-1994, 1995-1999, 2000-2004, and for Breslow thickness classes (< or =1, 1.01-2.00, >2 mm). The annual percent change (APC) of the standardized rates was computed. Thickness was evaluated on the basis of sex, age, morphology type, site and period of time. Median thickness was evaluated by means of a nonparametric K-sample test. The incidence rate of melanoma rose significantly for both invasive (APC=+5.1%) and in-situ lesions (APC=+11.1). The sex distribution of patients with invasive melanoma did not change over time (mean male/female ratio 0.95). The mean age at diagnosis did not change (57.2 years; SD=17.2 years). From 1985-1989 to 2000-2004 the median value of thickness decreased from 1.68 to 0.8 mm (P<0.001). Within the Breslow categories the median value of thickness decreased significantly for thin melanomas (< or =1 mm) but not for intermediate (1.01-2.00) or for thick melanomas (>2 mm). Among the most common melanoma types, the median thickness decreased for superficial spreading melanomas but not for nodular melanomas. Over time, the incidence of melanoma has increased notably and the median thickness has decreased. However, median thickness has decreased only among thin melanomas, whereas it has not changed for thick melanomas, most of which are of the nodular type.

Background: Dermoscopy is able to correctly classify a higher number of melanomas than naked-eye examination. Little is known however about factors which may influence the diagnostic performance during practice. The aim of the study was to analyze the effect of size of the lesion on diagnostic performance of dermoscopy in melanoma detection. Methods: Eight dermatologists examined clinical and, separately, clinical and dermoscopic (combined examination) images of 200 melanocytic lesions previously excised [64 melanomas, 24 in situ and 40 invasive (median thickness 0.30 mm) and 136 melanocytic nevi]. After examination, diagnostic performance was analyzed in accordance with the major diameter of the lesions divided into 3 groups, i.e. small (less than 6 mm), intermediate (between 6 and 9 mm) and large (10 mm or more) lesions. These groups were shown to be highly comparable concerning the microstaging of melanomas (median thickness value 0.30, 0.22 and 0.32 mm, respectively). Results: Dermoscopy increased the diagnostic performance of naked-eye examination of both intermediate and large lesions [sensitivity value: +19.3 (p = 0.002) and +10.3 (p = 0.007); diagnostic accuracy value: +7.4 (p = 0.004) and +6.1 (p = 0.07)]. On the contrary, no statistically significant increase was found dealing with small lesions (sensitivity +3.7, p = 0.66; diagnostic accuracy –1.7, p = 0.55). Conclusions: The diagnostic improvement associated with the addition of dermoscopy to naked-eye examination is influenced by the size of the lesion, i.e. it is lacking with lesions up to 6 mm in diameter. The optimized use of dermoscopy in melanoma detection is obtained dealing with melanocytic lesions 6 mm in diameter or larger.