Objective:To analyze clinical and histopathological characteristics of infantile congenital melanocytic nevi (ICMN) .Methods:Clinical and pathological data were collected from 126 infants with confirmedly diagnosed congenital melanocytic nevi in Department of Dermatology, Xijing Hospital from January 2015 to January 2020, and were retrospectively analyzed. Chi-square test was used for comparisons of enumeration data.Results:Among the 126 patients with ICMN, 68 were males and 58 were females; 109 (86.5%) presented with skin lesions at birth; 73 (57.9%) were 2 - 3 years old at the first clinic visit. The skin lesions occurred on the head and face (76 cases, 60.3%) , trunk (24 cases, 19.1%) or extremities (26 cases, 20.6%) . There were 36 (28.6%) patients with small congenital nevi, 68 (54.0%) with M1-type medium-sized nevi, 13 (10.3%) with M2-type medium-sized nevi and 9 (7.1%) with giant nevi. Of 126 cases of ICMN, 121 (96.0%) had solitary lesions, 5 (4.0%) had multiple lesions, 44 (34.9%) had nevi with coarse hairs, 15 (11.9%) had nevi complicated by papules or hyperplastic nodules, and 6 (4.8%) had satellite lesions. Pathological subtypes included compound nevus (120 cases, 95.2%) , intradermal nevus (4 cases, 3.2%) , and junctional nevus (2 cases, 1.6%) . Under the microscope, the depth of the skin lesions was < 1 mm in 38 (30.1%) cases, 1 - 2 mm in 61 (48.4%) and > 2 mm in 25 (19.8%) , and 45 (35.7%) cases showed nevus cells infiltrating the subcutaneous fat layer or deeper tissues. Among the 126 ICMN lesions, common pathological features included nevus tissue maturation (100%, 2 cases of junctional nevi were excluded) , pigment granules in the stratum corneum (53 cases, 42.1%) , disordered/asymmetric distribution of nevus cells (80 cases, 63.5%) , scattered epidermal nevus cells (91 cases, 72.2%) , pagetoid spread of epidermal nevus cells (67 cases, 53.2%) , melanophages in the dermis (71 cases, 56.4%) , and nevus cells distributed along hair follicles/sebaceous glands (82 cases, 65.1%) . Special pathological features included nevus cells embedded in the vascular/lymphatic vessels (42 cases, 33.3%) , nevus cell lysis (45 cases, 35.7%) , fibromatous changes (25 cases, 19.8%) , involvement of the arrector pilli muscles (31 cases, 24.6%) , and mast cell infiltration (30 cases, 23.8%) . Pathological patterns of ICMN with different clinical features: the incidences of infiltration depth > 2 mm, pigment granules and columnar pigment granules in the stratum corneum were significantly higher in the giant nevi than in the small and medium-sized nevi ( χ2 = 7.93, 10.76, 5.89 respectively, all P < 0.05) ; the incidences of infiltration depth > 2 mm, epidermal spongiosis with scattered nevus cells, nevus cell nests distributed along the hair follicles/sebaceous glands, fibromatous changes and mast cell infiltration were significantly higher in the skin lesions with coarse hairs than in those without ( χ2 = 28.29, 8.11, 6.22, 7.92, 8.19 respectively, all P < 0.01) ; the incidences of pagetoid spread of epidermal nevus cells and atypical nevus cells were significantly higher in the skin lesions with papules/hyperplastic nodules than in those without papules/hyperplastic nodules ( χ2 = 4.92, 6.30 respectively, both P < 0.05) . Conclusions:The clinical and histopathological characteristics of ICMN are unique, and atypical nevus cells are common in ICMN. The diagnosis and treatment of ICMN need to be based on the combination of clinical and pathological characteristics.

Objective To investigate the effect of dihydroartemisinin(DHA)on the inflammatory response and skin wound healing in diabetic rats.Methods The ointment was prepared with Carbomer 980,Tween-80,glycerol,ultrapure water and sodium hydroxide as a base.DHA and ethyl nipagin were added and stirred evenly,resulting in DHA ointment.Fifty SPF-grade SD rats were used to create a diabetic rat model by intraperitoneal injection of streptozotocin,and 44 rats were successfully modelled.Whole skin defect wounds were created on the back of rats by using a 2.0 cm diameter circular punch.Thirty-six dorsal wounds were randomly divided into 4 groups(n=9)by the random number table.Then the wounds were applied respectively with 5%DHA,10%DHA,15%DHA and ointment base(control group)once a day for 14 consecutive days.On the 3th,7th and 14th days,the wound healing was observed,the specimens were cut from 0.2 cm of wound margin and would tissue,the histological changes were observed by HE staining.Collagen changes were observed by Masson staining,and the concentrations of interleukin 6(IL-6),interleukin 10(IL-10),and tumor necrosis factor-α(TNF-α)were detected by ELISA.The other eight rats were randomly divided into 10%DHA group and control group.The tissue was cut from the wound on the 7th day,and transcriptome sequencing was performed by high-throughput sequencing technology to screen the differentially expressed genes(DEGs)between the two groups.Gene ontology(GO)functional enrichment analysis as well as kyoto encyclopedia of genes and genomes(KEGG)enrichment analysis were performed.Data were analyzed by one-way ANOVA using SPSS 27.0 statistical software.Results The different concentrations of DHA groups showed better wound healing rates than the control group.The 10%DHA group has the most significant effect(P＜0.05).Compared with the control group,each DHA group showed a decrease in inflammatory cell infiltration and an increase in collagen fibre area on the 7th and 14th days(P＜0.05).The expressions of IL-6 and TNF-α in each DHA group were significantly lower than those in the control group(P＜0.05),while the expression of IL-10 was significantly higher than that in the control group(P＜0.05).Differential gene volcano map showed that the 10%DHA group remarkably up-regulated anti-inflammatory and antibacterial genes such as hypoxia inducible factor 1α(Hif-1α),Smad homolog 12(Smad12)and β-defensin 4(Defb4).The GO functional enrichment analysis indicated that the 10%DHA group was significantly enriched in inflammatory response,immune response and defense response to bacterium.The KEGG enrichment analysis showed that the 10%DHA group was significantly enriched in chemokine signaling pathway,NOD-like receptor signaling pathway and so on.Conclusion DHA may inhibit excessive inflammatory responses by modulating inflammatory factors,anti-inflammatory and antimicrobial genes,chemokine signaling pathway and NOD-like receptor signaling pathway as well as reducing inflammatory cell infiltration,thereby enhancing wound healing.