BACKGROUND: Previous studies have revealed a potential link between inflammatory bowel disease (IBD) and seborrheic keratosis (SK). However, whether this association is causal or confounded remains unknown.
METHODS: We conducted this two-sample Mendelian randomization (TSMR) analysis to clarify bidirectional causality between IBD, including its two primary conditions Crohn\'s disease (CD) and ulcerative colitis (UC), and SK. The summary genetic data of IBD, CD, UC and SK were obtained from accessible genome-wide association studies (GWAS). This TSMR study was primarily performed using inverse-variance weighted (IVW) method, complemented by MR-Egger, weighted median (WM), Bayesian weighted MR (BWMR), MR-robust adjusted profile score (MR-RAPS), MR-pleiotropy residual sum and outlier (MR-PRESSO), and radial IVW MR analyses with modified second-order weights (IVW [Mod 2nd]) methods. Assessment of sensitivity and identification of potential outliers were subsequently conducted to aid interpretation of results.
RESULTS: The forward MR results showed that IBD [odds ratio (OR) = 1.068, 95% confidence interval (CI) = 1.010-1.129, p = 0.020) and its subtype CD (OR = 1.088, 95%CI = 1.038-1.139, p < 0.001) increased the risk of SK. However, the occurrence of SK could not be affected by UC (OR = 1.090, 95%CI = 0.977-1.216, p = 0.123). In the reverse analysis, no causal relationship between SK and IBD (OR = 0.905, 95%CI = 0.813-1.008, p = 0.069), UC (OR = 0.959, 95%CI = 0.860-1.068, p = 0.443), and CD (OR = 0.933, 95%CI = 0.846-1.029, p = 0.165) was identified.
CONCLUSIONS: These findings demonstrate that IBD and its subtype CD could increase the incidence of SK in European populations, whereas SK does not affect IBD occurrence.

Seborrheic keratosis (SK) is a common benign tumour, often associated with hyperpigmentation. To investigate the mechanism of melanin accumulation in SK, we have conducted comprehensive gene expression and histological analyses. We obtained five pairs of skin samples, including non-lesional and SK samples, from the backs of three male Japanese participants aged 40-59 years. To examine melanocytes and keratinocytes in SK, three pairs of skin samples were separated by laser capture microdissection into the basal layer and the other layer in the epidermis. We performed a comprehensive gene expression analysis to identify differentially expressed genes between non-lesional and SK skin, followed by gene ontology and pathway analysis. We found abnormal morphogenesis and cell proliferation in the basal layer, along with increased immune response and impaired cell differentiation and metabolism in the other layer of SK. We focused on cell proliferation and differentiation, as these are directly associated with melanin accumulation. Immunohistochemical analyses of Ki67, keratin 10, and keratin 14 demonstrated the decreases in the proliferation and early differentiation of the epidermis. Contrarily, no significant changes were observed in terminal differentiation markers, filaggrin and loricrin. Although the number of melanocytes was higher in SK than in non-lesional skin, melanogenic activity showed no difference. These results indicated that melanin accumulation in SK is caused by delayed melanin excretion due to reduced turnover around the basal and spinous layers of the epidermis and melanin production due to an increased number of melanocytes. Our findings provide new insights for therapeutic approaches in SK.

Seborrheic keratosis (SK) is a common skin disease in the elderly. However, in cases where SK presenting as multiple skin-colored or clustered lesions can be easily misdiagnosed as verruca plana (VP), especially in the young population. This retrospective study investigated the prevalence of SK and VP in the lesions that appear clinically similar to VP according to age. We examined the pathology slides of the skin tissue and photographs of patients who were clinically suspected to have VP. A total of 503 patients were included in the study, out of which 174 patients were finally diagnosed with SK (34.6%) and 132 with VP (26.2%). The mean ages of the SK- and VP-diagnosed group were 39.3 and 35.4 years, respectively. SK had a higher prevalence among individuals older than 30 years, and relative frequency of SK should not be ignored in patients with a grouped distribution in their 20 s and 30 s. Therefore, our study suggests that multiple verrucous skin-colored to brownish plaques are also commonly diagnosed as SK in young people as well as VP, and the prevalence of SK and VP may not always depend solely on chronological aging, and the prevalence of SK among young people may be higher than commonly believed stereotypes suggest.

暂无摘要。

OBJECTIVE: Tumor of follicular infundibulum (TFI) has been described as a neoplasm - isolated and multiple - and in association with other lesions. Its histopathologic definition is controversial.
METHODS: We present a histopathologically analyzed series of 28 patients with TFI features. This has been supplemented by a search in MEDLINE on the literature on this subject. The corresponding figures given in these articles have been discussed and analyzed.
RESULTS: Patients comprised 16 women and twelve men. TFI features were seen in five patients with nevus sebaceous, two trichofolliculomas, one dilated pore Winer, eight viral warts, one dermatofibroma, six seborrheic keratoses, three actinic keratoses, one invasive squamous cell carcinoma, and one basal cell carcinoma in association with a squamous cell carcinoma/actinic keratosis. After study of the literature especially of solitary cases of TFI, we interpret such cases mostly as variants of seborrheic keratoses with variable degree of infundibular, isthmic and/or sebaceous differentiation with or without regression.
CONCLUSIONS: We regard TFI as an epithelial growth pattern which may occur in hamartomatous, inflammatory, infectious, reactive, or neoplastic conditions, in most solitary forms likely best classified within the histopathological spectrum of seborrheic keratoses.

Benign tumors of the eye and eyelid are common in children and adults, and they rarely undergo malignant transformation. Their workup and management have evolved over the years with increasing advancements in surgical and laser therapies. This contribution focuses on describing the following benign eye and eyelid tumors and their diagnostic and treatment approaches: congenital and acquired melanocytic nevi; nevus of Ota (Hori nevus); conjunctival papilloma; seborrheic keratosis; epidermoid cyst; dermoid cyst; milium; xanthelasma; hemangioma (cherry angioma and pyogenic granuloma); neurofibroma; neurilemmoma (schwannoma); and fibroepithelial polyp. Surgical removal is the primary treatment approach for many of these benign tumors. With advancements in laser technologies, there are now several laser types that can be used in the treatment of these benign eye and eyelid tumors. Other treatment modalities include cryosurgery, electrosurgery, and topical or intralesional medications. We hope this review will provide a reference to dermatologists and ophthalmologists in their approach to evaluation and management of benign eye and eyelid tumors.

Seborrheic keratosis(SK) is a very common skin tumor which is mostly frequently observed in the trunck, head, neck. SK in the auricle is rare and this condition should be excluded the possibility of malignancy by pathologic diagnosis. We report a case of 66-year-old man who presented with a brownish, papillomatous, verrucous mass in the auricle for the past seven years, which began to growing faster during the previous year. Dermoscopy and histopathological examination were performed and the patient was diagnosed with SK. He was treated with the carbon dioxide(CO2) laser and aminolevulinate photodynamic therapy (ALA-PDT). The CO2 laser was used for the removal of the thick hypertrophic lesions and to enhance the transdermal absorption efficiency of ALA. A 20% ALA cream(118 mg/cm2) was applied to his lesion and sealed for 3 h without light, followed by irradiation with 630-nm LED light (96 J/cm2, 80 mw/cm2). We use fluorescent diagnosis with aminolevulinic acid to define the tumor margins at the first session of ALA-PDT. After 4 sessions of ALA-PDT, the lesion was completely removed and did not recur. Therefore, we consider that ALA-PDT combined with CO2 laser is a safe and effective choice for the treatment of seborrheic keratosis in the auricle.

暂无摘要。

BACKGROUND: Dermoscopic and reflectance confocal microscopy (RCM) correlations between morphologic groups of melanoma have not yet been described.
OBJECTIVE: Describe and compare dermoscopic and RCM features of cutaneous melanomas with histopathological confirmation.
METHODS: Single center, retrospective analysis of consecutive melanomas evaluated with RCM (2015-2019). Lesions were clinically classified as typical, nevus-like, amelanotic/nonmelanoma skin cancer (NMSC)-like, seborrheic keratosis (SK)-like and lentigo/lentigo maligna (LM)-like. Presence or absence of common facial and nonfacial melanoma dermoscopic and RCM patterns were recorded. Clusters were compared with typical lesions by multivariate logistic regression.
RESULTS: Among 583 melanoma lesions, significant differences between clusters were evident (compared to typical lesions). Observation of dermoscopic features (>50% of lesions) in amelanotic/NMSC-like lesions consistently displayed 3 patterns (atypical network, atypical vascular pattern + regression structures), and nevus-like and SK-like lesions and lentigo/LM-like lesions consistently displayed 2 patterns (atypical network + regression structures, and nonevident follicles + heavy pigmentation intensity). Differences were less evident with RCM, as almost all lesions were consistent with melanoma diagnosis.
CONCLUSIONS: Small SK-like lesions sample, single RCM analyses (no reproduction of outcome).
CONCLUSIONS: RCM has the potential to augment our ability to consistently and accurately diagnose melanoma independently of clinical and dermoscopic features.

Actinic keratoses (AK) are common premalignant skin lesions with a small risk of progressing to cutaneous squamous cell carcinoma (SCC). There is some evidence that patients with AKs also have increased risks of other skin cancers beyond SCC. However, the absolute risks of skin cancer in patients with AKs are unknown.
To calculate the absolute and relative risks of future skin cancer in Medicare beneficiaries with AKs.
This retrospective cohort study was performed using a deidentified, random sample of 4 999 999 fee-for-service Medicare beneficiaries from 2009 through 2018. Patients with treated AKs were included, and patients with seborrheic keratoses (SKs) were included as a comparator group. All patients were required to have at least 1 year between data set entry and first AK or SK. Patients with a history of skin cancer were excluded. Data were analyzed from September 2022 to March 2023.
Outcomes were first surgically treated skin cancer, including keratinocyte carcinoma (including SCC and basal cell carcinoma [BCC]) and melanoma. The absolute risks of skin cancer in patients with AKs were evaluated. Skin cancer risks in patients with AKs were compared with patients with SKs using adjusted competing risks regression.
A total of 555 945 patients with AKs (mean [SD] age, 74.0 [7.4] years; 55.4% female) and 481 024 patients with SKs (mean [SD] age, 73.3 [7.3] years; 72.4% female) were included. The absolute risk of skin cancer after a first AK was 6.3% (95% CI, 6.3%-6.4%) at 1 year, 18.4% (95% CI, 18.3%-18.5%) at 3 years, and 28.5% (95% CI, 28.4%-28.7%) at 5 years. Patients with AKs had increased risk of skin cancer compared with patients with SKs (any skin cancer: adjusted hazard ratio [aHR], 2.17; 95% CI, 2.15-2.19; keratinocyte carcinoma: aHR, 2.20; 95% CI, 2.18-2.22; SCC: aHR, 2.63; 95% CI, 2.59-2.66; BCC: aHR, 1.85; 95% CI, 1.82-1.87; and melanoma: aHR, 1.67; 95% CI, 1.60-1.73).
In this cohort study, older patients with AKs had substantial absolute risks, as well as elevated relative risks, of skin cancer. AKs may be clinical markers of UV exposure and increased skin cancer risk, including SCC, BCC, and melanoma. However, guidelines are lacking for follow-up skin cancer surveillance in patients with AKs. Efforts to develop evidence-based recommendations for skin cancer surveillance in patients with AKs are paramount.