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.

A 75-year-old man presented with an abdominal enlarging painless tumor of the skin evolving over the last 30 years. His past medical history was unremarkable. Physical examination revealed a brownish pedunculated cutaneous mass which had an irregular keratotic warty surface with no discharge or ulceration. The mass was clinically presumed to be a melanocytic tumor, or a verrucous carcinoma. A monoblock excision of the mass was performed with a good outcome. The specimen was then sent to our pathology department to rule out malignancy. Macroscopic examination revealed a brownish tumor of 7.5 × 7 × 1.5 cm which had fissures and cauliflower-like appearance. Final histological report concluded to a giant seborrheic keratosis.

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Actinic keratosis (AK) and seborrheic keratosis (SK) represent prevalent dermatological conditions with distinct clinical characteristics and potential health implications. This article investigates recent strides in dermatological diagnostics, centered on the development and application of artificial intelligence (AI) technology for discerning between AK and SK. The objective of this study is to develop and evaluate an artificial intelligence (AI) model capable of accurately distinguishing between stage one and stage two gastric carcinoma based on pathology slides. Employing a dataset of high-resolution images obtained from Kaggle.com, consisting of 1000 AK and 1000 SK images, a novel AI model was trained using cutting-edge deep learning methodologies. The dataset underwent meticulous partitioning into training, validation, and testing subsets to ensure robustness and generalizability. The AI model showcased exceptional proficiency in distinguishing AK from SK images, attaining notable levels of accuracy, precision, recall, specificity, F1-score, and area under the curve (AUC). Insights into the etiology and clinical ramifications of AK and SK were presented, emphasizing the critical significance of precise diagnosis and tailored therapeutic approaches. The integration of AI technology into dermatological practice holds considerable potential for enhancing diagnostic precision, refining treatment decisions, and elevating patient outcomes. This article underscores the transformative impact of AI in dermatology and the importance of collaborative efforts between clinicians, researchers, and technologists in advancing the realm of dermatological diagnosis and care.

UNASSIGNED: Seborrheic keratosis (SK) are benign lesions with cosmetic concerns. Role of TCA and erbium YAG laser has already been described individually in the literature. However, there is a scarcity of data on the comparative evaluation of these two modalities in SK.
UNASSIGNED: The aim of this study was to compare the efficacy and safety profile of Erbium YAG laser ablation with 70% TCA for the treatment of facial SK.
UNASSIGNED: A total of 50 cases of facial SK were included in the study. Group A included SK lesions on the right side of face treated with Erbium YAG laser ablation while Group B included SK lesions on the left side of face treated with topical 70% trichloroacetic acid. Repeated sessions of laser and TCA application were given at 2-week intervals till cure was achieved or up to a maximum of three sessions. Grading of response to treatment was assessed as complete response (100% clearance), partial response (>50 to 99% improvement), and inadequate or no response (<50% improvement).
UNASSIGNED: Complete clearance was observed in 40 (80%) and 29 (58%) cases in Groups A and B, respectively. There was a statistically significant difference in clearance rates between the two groups (P = 0.019). Number of sessions was significantly lesser in laser group (mean ± SD = 1.24 ± 0.43) than in the 70% TCA group (mean ± SD = 1.88 ± 0.79) (P = 0.001). Statistically significant lesser downtime was observed in group A (P = 0.001). Patient satisfaction rate was much higher in group A. Hyperpigmentation was more common in group B (TCA).
UNASSIGNED: Although both the treatment modalities achieved good results, erbium YAG laser ablation showed superior results than 70% TCA with better patient satisfaction rates but more downtime. Also, no major adverse effects were observed in the two groups.

Background: High-Intensity Focused Ultrasound (HIFU) has emerged as a precise and non-invasive modality for tissue ablation and healing. This study presents a detailed dermoscopic analysis of skin healing post-High-Intensity Focused Ultrasound (HIFU) treatment, focusing on common benign skin lesions, such as seborrheic keratosis, sebaceous hyperplasia, vascular lesions, and sebaceous nevi. Methods: Prior to HIFU treatment, a comprehensive assessment was conducted, integrating ultrasound scanning and clinical evaluations. The TOOsonix System ONE-M was employed for HIFU treatments, with parameters tailored to each lesion type. Results: A common pattern observed across all lesions includes initial whitening post treatment, followed by scab formation and the development of a pink area with reparative vessels. This study, however, highlights distinct differences in fibrosis patterns and healing timelines across different lesion types. Each lesion type exhibited unique fibrosis patterns post treatment. Flatter variants of seborrheic keratosis healed within a month, displaying hypopigmentation and reparative vessels, alongside a distinct lattice fibrosis pattern in more verrucous forms, which took about two months to heal. Sebaceous hyperplasia, characterized by rapid healing within three weeks, demonstrated fibrosis with pink areas and perpendicular white lines, concluding with a slight depression. Vascular lesions varied in healing time based on depth, with superficial ones showing whitening and crust formation, while deeper lesions had vessel occlusion and size reduction accompanied by concentric fibrotic bands. Sebaceous nevi presented the longest healing duration of three months, characterized by amorphous white-gray structures, scab formation, and the emergence of pink areas with branching vessels, leading to clear skin with reduced white lines. Conclusions: in conclusion, this meticulous clinical evaluation highlights the unique healing characteristics and timelines for each skin lesion type treated with HIFU. These insights are invaluable for optimizing follow-up assessments, identifying potential complications, and refining treatment protocols. By providing detailed insights into the healing timelines and patterns for different types of lesions, patients can be better informed about their post-treatment journey.

We present a clinical case of a 50-year-old female initially suspected of seborrheic keratosis but later diagnosed with melanoma through biopsy. This case highlights the challenges in distinguishing between these two conditions and emphasizes the importance of accurate diagnosis. Overdiagnosis of malignancy in seborrheic keratosis cases and the accurate identification of melanoma through dermoscopy are discussed. Further research is needed to explore potential mechanistic connections between seborrheic keratosis and melanoma.

UNASSIGNED: Der Tumor des follikulären Infundibulums (TFI) wurde als Neoplasie - isoliert und multipel - und in Assoziation mit anderen epithelialen Läsionen beschrieben. Seine endgültige histopathologische Definition wird kontrovers diskutiert.
UNASSIGNED: Wir präsentieren eine retrospektive Serie von 28 Patienten mit TFI beziehungsweise TFI-ähnlichen Veränderungen. Ergänzend wurde die in MEDLINE aufgeführte Literatur zum Thema TFI recherchiert und die darin publizierten Abbildungen interaktiv diskutiert und analysiert.
UNASSIGNED: Unsere Patienten waren 16 Frauen und 12 Männer. TFI-ähnliche Veränderungen fanden sich bei fünf Patienten mit Nävus sebaceus, zwei Trichofollikulomen, einer erweiterten Pore Winer, acht Virusakanthomen, einem Dermatofibrom, sechs seborrhoischen Keratosen, drei aktinischen Keratosen, einem invasiven Plattenepithelkarzinom und einem Basalzellkarzinom in Kombination mit Plattenepithelkarzinom/aktinischer Keratose. Nach Sichtung der Literatur, insbesondere von solitären Fällen von TFI, betrachten wir diese größtenteils als Variante von seborrhoischen Keratosen mit variablem Ausmaß von infundibulärer, isthmischer und/oder sebazärer Differenzierung mit oder ohne Regression.
UNASSIGNED: Wir werten TFI insgesamt als ein epitheliales Wachstumsmuster, das bei hamartomatösen, entzündlichen inkludierend infektiösen, reaktiven oder neoplastischen Prozessen auftreten und in den meisten solitären Formen am ehesten innerhalb des histologischen Spektrums seborrhoischer Keratosen eingeordnet werden kann.

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.