Evaluation of the ability of patients to identify enlarging melanocytic nevi.
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Cell Transformation, Neoplastic↗
Biomedical subjects
M Dawid
Publications and source records attributed to M Dawid.
Mechanism of migration of the trimethylsilyl group during reactions of methoxy[(trimethylsilyl)ethoxy]carbene with N-phenylmaleimide and C(60).
A novel migration of the trimethylsilyl group during reaction of methoxy[(trimethylsilyl)ethoxy]carbene with N-phenylmaleimide (NPM) and with C(60), reported earlier, was examined by means of deuterium labeling of the carbene. For the NPM case it was found that the CD(2)CH(2)SiMe(3) group, initially bound to oxygen, became the CH(2)CD(2)SiMe(3) group bound to carbon in the end product. Not only had the trimethylsilylethyl group moved from oxygen to carbon, but the TMS group had also migrated 1,2 along the ethyl chain. For the C(60) case, complete scrambling of the CD(2) group was observed, strongly implying the involvement of a silacyclopropane carbocation responsible for product formation. The labeling study supports the mechanism that was tentatively advanced earlier for addition to NPM and one of the possibilities suggested for addition to C(60).
Journal Article↗
The first 2,2-dialkoxythiirane.
[reaction: see text] Thermolysis of 1 at 110 degrees C in benzene containing adamantanethione leads to thiirane 2 in 92% yield, as an isolable, stable solid. Compound 2 is the first example of the hitherto unknown 2,2-dialkoxythiiranes. It shows some reactions characteristic of thiiranes.
Journal Article↗
Frequency and characteristics of enlarging common melanocytic nevi.
OBJECTIVE: To analyze the frequency and characteristics of enlarging common melanocytic nevi. DESIGN: Cohort study using digital epiluminescence microscopy (ELM) for documentation and follow-up, with a median follow-up interval of 11.4 months. SETTING: A dermatology department at a university hospital in Vienna, Austria. PATIENTS: One thousand six hundred twelve melanocytic nevi appearing clinically as common nevi, obtained from 385 patients (mean [+/-SD] age, 34.2 +/- 14.8 y; 55.6% female). INTERVENTIONS: Follow-up examination and documentation by digital ELM. MAIN OUTCOME MEASURES: Frequency of enlarging nevi according to age and comparison of ELM features observed in enlarging and nonenlarging nevi. RESULTS: Enlargement was found in 5.3% (n = 86) of nevi. The frequency of enlarging nevi was inversely related to age (P<.001), in that enlarging nevi were common in patients younger than 20 years and relatively rare in older age groups. Epiluminescence microscopy revealed a peripheral rim of brown globules in 48.8% (n = 42) of enlarging nevi. In contrast, a peripheral rim of brown globules was found in only 0.7% (n = 11) of nevi without enlargement (P<.001). Enlarging nevi that were excised in children and adolescents showed no histological signs of atypia. In older age groups, 48.1% of excised enlarging nevi that were clinically diagnosed as common nevi showed some histological signs of atypia. None of the excised enlarging lesions was histologically diagnosed as melanoma. CONCLUSIONS: The frequency of enlarging common nevi is inversely related to age. In the absence of clinical signs of atypia, enlargement alone does not indicate malignancy. A peripheral rim of brown globules is a characteristic ELM feature of symmetrically enlarging melanocytic nevi.
Adult↗
Reevaluation of the ABCD rule for epiluminescence microscopy.
BACKGROUND: Epiluminescence microscopy (ELM) provides for increased accuracy in the clinical diagnosis of pigmented skin lesions (PSL). It is based on pattern analysis of ELM criteria, which requires experience. The recently introduced application of the ABCD score to ELM facilitates this by permitting lesion evaluation on the basis of predefined clinical criteria. OBJECTIVE: The present study was performed to evaluate the diagnostic performance of the ABCD rule for ELM in pigmented skin lesions testing dermatologists with varying skills from novice to expert. METHODS: Two hundred fifty electronic images of randomly selected, histologically proven PSL including 41 early melanomas (16.4%) were presented to the raters, and each image was scored according to the rules of the ABCD score and rated without the guidance of a scoring system on a scale from 1 = definitely benign to 5 = definitely melanoma. RESULTS: Our data show that the application of the ABCD rule significantly enhances diagnostic ability in less experienced dermatologists compared with rating without the guidance of a scoring system. In contrast, the diagnostic accuracy of dermatologists who are moderately to greatly experienced is not improved by use of the ABCD rule. CONCLUSION: Our experiments indicate that the application of the ABCD rule to ELM introduced by Stolz et al represents a useful enhancement for diagnosis of pigmented skin lesions in less experienced users. However, the method does fail to detect melanomas with 100% accuracy. Therefore further effort has to be made to make the diagnosis of melanoma easier and more accurate.
Clinical Competence↗
Morphologic changes of pigmented skin lesions: a useful extension of the ABCD rule for dermatoscopy.
BACKGROUND: Epiluminescence microscopy (ELM) significantly increases the early diagnosis of pigmented skin lesions (PSL) using established criteria and pattern analysis. The ABCD rule for dermatoscopy (ie, ELM) provides a simplified approach to the interpretation of ELM images on the basis of asymmetry (A), border (B), color (C), and dermatoscopic structure (D). OBJECTIVE: We set out to determine whether the diagnostic accuracy of the ABCD scoring algorithm can be significantly improved by incorporating information about morphologic changes of the lesion observed and provided by the patient. METHODS: We prospectively collected 356 small pigmented skin lesions (< 1 cm) including 73 (20.5%) melanomas. Before excision all patients were asked whether the lesion had changed in size, color, or shape within the last year or whether they experienced any sign of ulceration or spontaneous bleeding. ELM images of the lesions were evaluated according to the ABCD rule for dermatoscopy to yield a semiquantitative score. Accuracy of diagnosis was evaluated in terms of sensitivity, specificity, and area under receiver operating characteristic curves (AUC). RESULTS: The frequency of reported changes was significantly higher for melanomas than benign PSL (65.8% vs 29.7%, P < .001). In a multivariate model morphologic change was a significant independent predictor of malignancy (odds ratio = 3.17, 95% confidence interval [CI]: 1.96 to 5.14, P < .001). The mean final score achieved when using the enhanced ABCD-E criteria including morphologic change (E) was significantly higher for melanomas (5.7, 95% CI: 5.3 to 6.0) than benign PSL (2.9, 95% CI: 2.8 to 3.1, P < .001). Diagnostic accuracy was significantly higher when the lesions were evaluated by the enhanced ABCD-E criteria as compared with the standard ABCD score (AUC(ABCD) = 0.87 vs AUC(ABCD-E) = 0.90; P = .006). CONCLUSION: Information about morphologic changes of PSL as reported by the patient is a useful extension of the ABCD rule for dermatoscopy.
Adult↗