Objective:To investigate the expression of anaplastic lymphoma kinase (ALK), tropomyosin receptor kinase (TRK), and recombinant C-Ros oncogene 1, receptor tyrosine kinase (ROS1) in Spitz tumors, and to analyze their associations with clinical and histopathological features of Spitz tumors.Methods:Clinical and histopathological characteristics, as well as follow-up data, were collected from patients with Spitz tumors at Department of Pathology, Hospital of Dermatology, Chinese Academy of Medical Sciences from January 2017 to August 2023, and retrospectively analyzed. Immunohistochemical staining for ALK, pan-TRK, and ROS1 was performed on skin tissues, and associations between the expression of these kinase proteins and clinicopathological features were analyzed.Results:A total of 57 patients with Spitz tumors were collected, including 36 females and 21 males. Immunohistochemical staining showed that 30 (52.6%) patients were positive for ALK, 4 (7.0%) were positive for ROS1, only 2 (3.5%) were positive for TRK, and 21 (36.8%) were negative for the three kinase proteins. Among the 30 ALK-positive patients, the median age was 9.5 years, 21 (70.0%) were females, and 15 (50.0%) presented with lesions on the face, which mainly manifested as papules or nodules; histologically, 29 (96.7%) patients had hypopigmented tumors with an exophytic growth pattern, and the tumor cells were mainly large and long spindle cells arranged in long cord-like, plexiform or fascicular patterns. Among the 4 ROS1-positive patients, there were 3 females and 1 male, presenting with exophytic papules or polyps; histologically, tumor cells were mostly arranged in small nests, without obvious clefts around cell nests. Two TRK-positive patients were both males aged 20 and 50 years respectively, and presented with brown and skin-colored flat papules, respectively; histologically, the tumors were located superficially with a flat base, and tumor cells spread in a pagetoid pattern in the epidermis, with some epithelioid cells and small cell nests. Among the 21 patients negative for the 3 kinase proteins, 9 were males and 12 were females, and they clinically presented with macules, papules and polypoid lesions; histologically, most tumors were located superficially, consisting of a mixture of epithelioid cells and spindle cells, with rare cytological atypia and mitotic figures, and 2 cases showed mild tissue structural and cellular atypia. Fifty-seven patients were followed up for 2 - 83.3 months, with a median follow-up of 19.2 months. Only 1 ALK-positive child experienced a recurrence, and no recurrence or lymph node metastasis was observed in the other cases.Conclusions:Among the three kinase proteins, ALK showed the highest positive rate in Spitz tumors in this study, while TRK- and ROS1-positive cases were sporadic. Histopathologically, ALK-positive Spitz tumor cells were mainly long spindle cells arranged in long cord-like or plexiform patterns, while TRK- and ROS1-positive Spitz tumors tended to have small cell nests. Both the kinase protein-positive and -negative Spitz tumors mostly had a good prognosis.

Objective:To investigate clinical and histopathological features and differential diagnostic considerations of mucoepidermoid carcinoma (MEC) .Methods:A retrospective study was carried out on clinical manifestations, histopathological and immunohistochemical features, treatment and prognosis of 8 patients with MEC, who were collected from Department of Pathology, Hospital of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College during 2018 - 2021.Results:Among the 8 patients, 5 were males and 3 were females, and their age at onset ranged from 19 to 67 years. Skin lesions were located on the lip mucosa in 5 cases, on the cheek in 2 cases, and on the nose in 1 case. Tumors were all located in the dermis and subcutaneous tissue, parts of which were connected to the epidermis; different proportions of mucous cells, epidermoid cells and intermediate cells were arranged in nests or clumps, and formed solid or cystic structures accompanied by varying degrees of formation of ducts and mucus lakes; all epidermoid cells and intermediate cells expressed cytokeratins AE1/AE3, CK5/6, P63, carcinoembryonic antigen and epithelial membrane antigen. According to the current Chinese grading system, 1 of the 8 patients was diagnosed with intermediate-grade MEC, and others were diagnosed with low-grade MEC. No abnormalities were found by systemic examination. All patients received surgical resections. After the follow-up of 12 - 36 months, no recurrence or distant metastasis was observed.Conclusion:MEC presents no characteristic clinical manifestations, its diagnosis mainly depends on histopathological features, and mucus in the cytoplasm of mucous cells as shown by alcian blue staining is specific for MEC.

Objective:To investigate clinicopathological features and prognosis of transformed mycosis fungoides (TMF) .Methods:A retrospective analysis was performed on clinicopathological data collected from 24 patients with TMF, as well as on flow cytometry results of 16 peripheral blood samples obtained from 11 of the 24 patients, who visited Hospital of Dermatology, Chinese Academy of Medical Sciences between 2014 and 2020.Results:Among the 24 patients, 11 were males and 13 were females. Their average age at diagnosis of TMF was 50.0 years (range: 18 - 77 years), and patients with early-stage TMF (9 cases) and tumor-stage TMF (15 cases) were aged 44.8 and 52.6 years on average, respectively. The average time interval from diagnosis of MF to large cell transformation was 3.7 years, and 8 patients were diagnosed with TMF at the initial visit. Histopathologically, large cells infiltrated in a diffuse pattern in 20 cases, as well as in a multifocal pattern in 4, and the proportion of large cells in 7 cases was greater than 75%. Immunohistochemically, 18 patients showed positive staining for CD30, and the proportion of CD30-positive large cells was greater than 75% in 9; negative staining for CD30 was observed in 6. Flow cytometry of 16 peripheral blood samples showed the presence of cell subsets expressing clonal T cell receptor (TCR) -vβ in 2 of 4 patients with early-stage TMF and 10 of 12 with tumor-stage TMF, and tumor cells with higher forward scatter than normal lymphocytes were detected in 16 samples. During the follow-up, among the patients with early-stage TMF, 3 progressed to tumor-stage TMF 3.3 years on average after large cell transformation, 1 progressed to erythrodermic MF in stage IIIA, and the other 4 still showed an indolent course; among the patients with tumor-stage TMF, 1 progressed to stage-IV TMF, and 5 died 3.3 (1.5 - 6) years after large cell transformation.Conclusion:Large cell transformation may occur in patients with MF in any stage, some patients have poor prognosis, so close follow-up is needed for patients with TMF.

Objective:To investigate the expression of epigenetic inhibitor polycomb group proteins such as enhancer of zeste homolog 1/2 (EZH1/EZH2), embryonic ectoderm development protein (EED) and suppressor of zeste 12 (SUZ12) in common cutaneous T-cell lymphomas and lymphoproliferative disorders (CTCL/LPD) .Methods:Totally, 93 paraffin-embedded skin samples of CTCL/LPD and 8 of lichen planus were collected from Hospital for Skin Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College between 2012 and 2019, and subjected to immunohistochemical staining to determine the protein expression of EZH2, EED, SUZ12 and EZH1. Statistical analysis was carried out with SPSS 25.0 software by using chi-square test and Spearman correlation analysis.Results:The 93 cases of CTCL/LPD included 44 cases of mycosis fungoides (MF), 17 natural killer/T cell lymphoma (NK/TCL), 8 primary cutaneous anaplastic large cell lymphoma (PC-ALCL), 8 lymphomatoid papulosis (LyP), 8 hydroa vacciniforme-like lymphoproliferative disorder (HV-like LPD) and 8 cases of subcutaneous panniculitis-like T cell lymphoma (SPTCL). Among the 93 CTCL/LPD cases, 83 (89.2%) were positive for EZH2, 81 (87.1%) for EED, 78 (83.9%) for SUZ12 and 37 (39.8%) for EZH1; among the 8 cases of lichen planus, 1 was positive for EZH2, all were positive for EZH1, and all were negative for EED and SUZ12. The expression of EZH2, EED, SUZ12 and EZH1 in lichen planus samples significantly differed from all the CTCL/LPD samples ( χ2 = 41.75, 39.74, 39.36, 32.83, respectively, all P < 0.001), and from MF, NK/TCL, PC-ALCL, LyP, HV-like LPD and SPTCL samples separately (α = 0.008 3, all P < 0.001). Meanwhile, the score of EZH2 expression was negatively correlated with that of EZH1 expression in the MF, NK/TCL, PC-ALCL, LyP, HV-like LPD and SPTCL tissues ( rs = -0.60, -0.68, -0.89, -0.74, -0.93, -0.80, respectively, all P < 0.05) . Conclusion:Polycomb group proteins EZH2, EED, SUZ12 and EZH1 are abnormally expressed in CTCL/LPD lesions.

Objective: To describe the dermoscopic features of extramammary Paget′s disease (EMPD) and chronic eczema of the vulva, and to explore the value of dermoscopy in the diagnosis and differential diagnosis of the above diseases. Methods: Dermoscopic images were collected from 20 patients with histopathologically confirmed vulvar EMPD and 16 patients with clinically confirmed chronic eczema of the vulva in Hospital for Skin Diseases, Chinese Academy of Medical Sciences and Pekin Union Medical College from January 2017 to April 2018, and retrospectively analyzed. Fisher′s exact test was used to compare the prevalence of dermoscopic features between the two groups. Results: As dermoscopy showed, the milky red background was observed in 19 EMPD patients and in only 1 patient with chronic eczema, and there was a significant difference in the prevalence of milky red background between the two groups (P < 0.001) . White scales were the most common desquamation, and were observed in 9 EMPD patients and 13 patients with chronic eczema (P = 0.128) . Blood vessels were uniformly distributed in EMPD patients, including dotted-globular vessels in 19 and linear vessels in 14, while blood vessels were distributed in a patchy or clustered pattern in the patients with chronic eczema, including dotted-globular vessels in 16 and linear vessels in 7. There was a significant difference in the prevalence of different distribution patterns of blood vessels between the two groups (P < 0.001) . Bright white streaks, bright white structureless area and reticular structure were observed in 19, 20 and 19 EMPD patients respectively, and in 1, 1 and 1 patient with chronic eczema respectively, and there were significant differences in the prevalence of the above 3 structures between the two diseases (all P < 0.001) . Conclusion Vulvar EMPD and chronic eczema both show characteristic dermoscopic features, and dermoscopy is of great value to the diagnosis and differential diagnosis of EMPD.

Angiogenesis plays an important role in the occurrence,development and metastasis of malignant tumors,and anti?angiogenesis has become an important therapeutic method in molecular targeted therapy of tumors.At present, the commonly used anti?angiogenesis drugs include monoclonal antibodies (bevacizumab),tyrosine kinase inhibitors (sorafenib,sunitinib),and endothelial cell growth inhibitors.The adverse reactions of different kinds of targeted anti?angiogenesis drugs are different.To grasp the mechanism of adverse reactions and the treatment measures of related adverse reactions of these drugs will improve the tolerance of patients receiving this kind of drugs, and at the same time, the prognosis of patients will be further improved.

Objective To measure histidine triad nucleotide?binding protein 1(HINT1)protein expression and gene promoter methylation, and to analyze the relationship between HINT1 gene promoter methylation and clinical pathological features of melanoma. Methods Fifty?six patients with melanoma and 51 patients with nevus were enrolled as subjects and controls, respectively. Methylation?specific PCR (MSP) was performed to measure the methylation of HINT1 gene promoter in lesional and paratumoral tissue specimens from the patients with melanoma, as well as in lesional specimens from the patients with nevus. Immunohistochemistry was carried out to quantify the expression of HINT1 protein in these tissue specimens. Results MSP showed that the methylation rate of HINT1 gene promoter was significantly higher in melanoma tissues than in paratumoral and nevus tissues(76.8%[43/56]vs. 33.9%[19/56]and 35.3%[18/51], χ2 = 20.810 and 18.749, respectively, both P < 0.05), but was insignificantly different between paratumoral and nevus tissues(χ2=0.022, P>0.05). Immunohistochemistry revealed that the expression rate of HINT1 was 21.4%(12/56)in melanoma tissues, compared to 82.4%(42/51)in nevus tissues(χ2 = 39.633, P <0.01). There was a significant difference in the methylation rate of HINT1 promoter between HINT1?positive and ?negative melanoma tissues(6/12 vs. 37/44[84.1%], P<0.05), and between Clark levelⅠ-ⅡandⅢ-Ⅴmelanoma tissues(59.1%[13/22]vs. 88.2%[30/34],χ2=6.365,P=0.012). Conclusions HINT1 protein is lowly expressed in melanoma, which may be associated with high methylation of its gene promoter. Moreover, the high methylation ofHINT1 gene promoter may be involved in the initiation and progression of melanoma.

Objective To measure the expression of CC chemokine ligand 18(CCL18)in cutaneous malignant melanoma (CMM) tissues, and to explore its clinical significance, as well as relationship with vascular endothelial growth factor (VEGF) and Ki67 antigen expressions. Methods Immunohistochemistry was performed to measure CCL18, VEGF and Ki67 expressions in 58 paraffin?embedded CMM tissue specimens, as well as CCL18 expression in 20 paraffin?embedded pigmented nevus specimens, and immunofluorescence assay to confirm the expression of CCL18 in fresh CMM tissue specimens. Correlations of CCL18 expression with CMM clinicopathologic features, VEGF and Ki67 expressions were analyzed. Results CCL18 was detected in 49 (84.48%) of 58 paraffin?embedded CMM specimens, but in none of the 20 paraffin?embedded pigmented nevus specimens, with a significant difference in the positive rate of CCL18 between the CMM group and pigmented nevus group(χ2=45.46, P<0.01). The expression of CCL18 in paraffin?embedded CMM tissues was positively correlated with Clark′s level and Breslow thickness of CMM (rs = 0.609, 0.644 respectively, both P < 0.01), and was significantly different between ulcerated and non?ulcerated CMM(P<0.05), as well as between patients with and without lymphatic metastasis(P<0.05). However, there were no significant differences in the expression of CCL18 among patients of different age, gender, or between acral and non?acral CMM(all P>0.05). In addition, the expression of CCL18 in CMM tissues was positively correlated with that of VEGF(rs = 0.727, P < 0.05), but unrelated to that of Ki67(P > 0.05). Immunofluorescence assay showed CCL18 expression in the cytoplasm of tumor cells in CMM tissues. Conclusion CCL18 is highly expressed in CMM tissues, and may be involved in tumor invasion and metastasis.

Objective To measure the expression of hypoxia-inducible factor (HIF)-1α in acral malignant melanoma (MM) tissue and to investigate its relationship with the stem cell factor (SCF)/c-kit pathway.Methods Immunohistochemical staining was performed to measure the expression of HIF-1α in tissue specimens from lesions of 93 patients with acral MM,21 with non-acral MM,39 with acral melanocytic nevi,and from the normal acral skin of 15 healthy human controls.Meanwhile,the expression of c-kit was detected by immunohistochemical staining in the 93 acral MM tissue specimens.Statistical comparisons were carried out by chi-square test and Mann-Whitney U test.The relationship of HIF-1α expression with c-kit expression as well as tumor progression and staging was assessed by Spearman correlation analysis.Results Immunohistochemistry showed that the expression rate of HIF-1α was 87.10％ (81/93) in acral MM specimens,90.48％ (19/21) in non-acral MM specimens,15.38％ (6/39) in acral melanocytic nevus specimens,but 0 (0/15) in the normal acral skin specimens.The expression of HIF-1α was significantly higher in acral MM lesions than in normal acral skin and acral melanocytic nevus lesions (both P ＜ 0.01),and significantly different between acral MM and non-acral MM lesions (P ＜ 0.01).Moreover,HIF-1α expression was positively correlated with Clark level and Breslow depth of melanoma (rs =0.442,0.368,respectively,both P ＜ 0.01),with the progression of acral MM (from in situ to aggressive and metastatic MM) (rs =0.420,P ＜ 0.01),and with the expression of c-kit (rs =0.307,P ＜ 0.01).Conclusions HIF-1α is highly expressed in acral MM,positively correlated with the staging,progression and aggression of MM,and co-expressed with c-kit in acral MM tissue,suggesting that both HIF-1α and c-kit take part in the pathogenesis of acral MM.

Objective To detect the expression of tissue inhibitor of metalloproteinase-4 (TIMP-4) in cutaneous malignant melanoma (CMM) tissue and to assess its relationship with melanoma proliferation,invasion and metastasis.Methods Western blot was conducted to measure the protein expression of TIMP-4 in five fresh lesional and paratumoral tissue specimens of CMM and three fresh tissue specimens of nevi.Immunohistochemistry was carried out to quantify the expression of TIMP-4,Ki-67,matrix metalloproteinase-2 (MMP-2),vascular endothelial growth factor (VEGF) and CD63 in paraffin-embedded tissue samples from 43 cases of CMM and 51 cases of nevi.The degree of malignancy of melanoma was evaluated in these lesions.Results Western blot analysis showed that the expression of TIMP-4 was significantly higher in 4 of 5 CMM tissue specimens than in corresponding paratumoral tissue specimens and nevus tissue specimens.Immunohistochemistry revealed that the expression rate of TIMP-4 was 86.04％ (37/43) in melanoma tissue,compared to 19.6％ (10/51) in nevus tissue (x2 =31.55,P ＜ 0.05).The expression of TIMP-4 increased sequentially from in situ melanoma to invasive and metastatic melanoma (rs =0.309,P ＜ 0.05).As far as CMM was concerned,the TIMP-4 expression was uncorrelated with any of the known prognostic variables including clinical stage,Clark level,Breslow depth,presence of ulcer,and Ki-67 expression (all P ＞ 0.05),but positively correlated with the expressions of VEGF (rs =0.345,P ＜ 0.05) and CD63 (rs =0.555,P ＜ 0.01).The median expression level of TIMP-4 was significantly higher in MMP-2-positive than in MMP-2-negative melanoma tissue samples (3 vs.0,P ＜ 0.01).Conclusions TIMP-4 protein is highly expressed in CMM tissue,which may be closely associated with the initiation and progression of CMM,especially with the metastasis of and angiogenesis in CMM.