What Is Dermatoscopy?

Dermatoscopes are also known as transdermal microscopes. The English and synonymous names of Dermatoscope include Dermatoscope, Dermoscope, Epiluminescence Microscope (ELM), Incident light microscope, Skin surface microscope. Its function is the same as that of ophthalmology ophthalmoscope and otoscope for otolaryngology. It is a good tool for observing skin pigmented diseases.

Dermatoscope

Dermatoscopes are also known as transdermal microscopes. The English and synonymous names of Dermatoscope include Dermatoscope, Dermoscope, Epiluminescence Microscope (ELM), Incident light microscope, Skin surface microscope. Functional and ophthalmic

Dermatoscopy

The study included 198 consecutive atypical melanocyte lesions. Dermatoscopy evaluation criteria are based on the presence or absence of 23 dermoscopy features. Two dermatologists with dermoscopy experience used pattern analysis, dermoscopy ABCD rules, and a 7-point checklist to classify each lesion as benign or malignant. After surgical resection, 102 skin lesions were diagnosed histologically as Clack nevus and 96 skin lesions were diagnosed as TM. Dermatoscopy and histology diagnosis of TM were compared to evaluate the sensitivity, specificity, and diagnostic accuracy of these three standard diagnostic TMs, as well as their respective positive and negative predictive values. Univariate and multivariate analyses were used to determine which dermoscopy criteria were most closely related to TM.

The results showed that among the melanocyte lesions studied, 82.3% were correctly diagnosed by pattern analysis (sensitivity 85.4%, specificity 79.4%, positive predictive value 79.6%, and diagnostic accuracy 70.8%); compared with 79.3% were correctly diagnosed by the ABCD rule (sensitivity 84.4%, specificity 74.5%, positive predictive value 75.7%, and diagnostic accuracy 67.8%), and 71.2% were correctly diagnosed through a 7-point checklist (sensitivity 78.1%, specific (64.7%, positive predictive value of 67.6%, diagnostic accuracy rate of 57.7%). At the same time, the 7-point checklist has the highest false negative result (21.8%), while the ABCD rule and model analysis are 15.6% and 14.6%, respectively.

Univariate analysis shows that for TM, the atypical pigment network has sharp edges, a network of irregular, uneven brown small spheroids, uneven pigment distribution, homogeneous areas and light brown unstructured areas are the most sensitive And specific dermatoscopic features. The reverse stepwise logistic regression analysis showed that the index most closely related to TM was the light brown unstructured region (ratio of odds = 27.9).

Studies have shown that modal analysis has the highest sensitivity, specificity, and diagnostic accuracy. The light brown unstructured area is both a statistically significant indicator of differentiation and the most reliable predictor of TM (positive predictive value = 93.8%, positive likelihood ratio = 16). Researchers believe that the use of the previously underestimated dermoscopy diagnostic criteria for pattern analysis can not only improve the ability to diagnose suspicious spotted melanocyte lesions, but also significantly reduce false negative results from a 7-point checklist.

(Compiled by Qiu Meng, Zou Xianbiao, Dermatology Department, First Affiliated Hospital of PLA General Hospital, originally published in China Medical Tribune)