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Objective:To analyze 141 cases clinically misdiagnosed as melanoma, and to improve the understanding and diagnosis of diseases.Methods:Totally, 141 cases preliminarily diagnosed as melanoma, which was finally excluded according to histopathological examination results, were collected from the pathological database of Department of Dermatology, Xijing Hospital, The Fourth Military Medical University from November 2001 to September 2019, and their clinical and histopathological data were analyzed retrospectively.Results:Among the 141 cases clinically misdiagnosed as melanoma, 64 were males and 77 were females. Their median age at the time of misdiagnosis was 51 years, and the average disease duration was 103.4 months. The patients mainly presented with patches and papules, most of which were black in color. Based on histopathological manifestations, 35 patients were diagnosed with pigmented nevi, 29 with basal cell carcinoma, 15 with seborrheic keratosis, 7 with Bowen′s disease, 6 with nail melanin spots, 5 with epidermal cysts, 4 with poroma, 4 with hemorrhage, 4 with dermatofibroma, and 23 with other skin diseases.Conclusions:In clinical practice, some diseases with characteristics of melanoma are liable to be misdiagnosed. It is necessary to grasp their clinical features and actively carry out auxiliary examinations such as dermoscopy and histopathological examinations to confirm the diagnosis and reduce the misdiagnosis rate.
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Objective To determine the expression of miR-486-3p in psoriatic lesions and healthy human skin and to estimate its effect on keratin 17 (K17) expression in HaCaT human keratinocytes.Methods Bioinformatics was used to predict microRNAs that may affect the expression of K17.Tissue samples were obtained from the lesions of 10 patients with psoriasis and normal skin of 10 healthy human controls.RNA was extracted from these tissue samples and reversely transcribed into cDNA with the addition of a Poly (A) tail.Then,real time quantitative PCR was performed to measure the expression of miR-486-3p.Cultured keratinocytes were transfected with miR-486-3p mimics or negative control,and Western blot was performed to determine K17 expression at 48 hours after the transfection.To evaluate the inhibitory effect of miR-486-3p on K17 expression,cultured 293T cells were transfected with the plasmid containing K17 3' untranslated region (UTR) seed sequence,three plasmids containing the complete deletion,interval mutation or double repeats of the seed sequence,or negative control plasmid.At 24 hours after the transfection,a dualluciferase reporter (DLR) assay was performed to quantify the expression of K17.Results Real time PCR showed that the expression level of miR-486-3p was significantly lower in psoriatic lesions than in the normal skin (0.211 ± 0.120vs.0.555 ± 0.425,t =2.62,v =9,P ＜ 0.05).The HaCaT cells transfected with the mimics of miR-486-3p exhibited decreased expression of K17 compared with those transfected with the negative control.DLR assay revealed that the expression level (fluorescence intensity) of K17 in the negative control group was significantly higher than that in the 293T cells transfected with the seed sequence and those with the double repeats of the seed sequence (100.00％ vs.65.31％ ± 6.32％ and 54.18％ ± 10.01％ respectively,both P ＜ 0.05),but did not differ from that in the 293T cells transfected with the complete deletion and interval mutation of the seed sequence (100.00％ vs.114.77％ ± 16.14％ and 110.21％ ± 12.99％ respectively,both P ＞ 0.05).Conclusions The expression of miR-486-3p,which may inhibit K17 expression by binding to the seed sequence of K17 3'UTR,is lower in psoriatic lesions than in normal skin.The decreased expression and inhibitory effect of miR-486-3p may be implicated in the initiation and progression of psoriasis.