Abstract Seborrheic keratosis (SK) is a common benign cutaneous neoplasm; however, rare cases of malignant transformation to squamous cell carcinoma (SCC) have been reported. This study aimed to investigate the clinical and histopathological characteristics of SCC arising within SK (SCC-SK). We retrospectively reviewed 360 SCC lesions in 345 patients treated at a single institution between October 2014 and December 2022. Two definite SCC-SK cases (0.56% of all SCC lesions) were identified among 360 SCC lesions, together with one additional probable case in which SCC developed at the same site as biopsy-proven SK 6 years earlier, yielding an overall frequency of 0.83%. All patients were in their 90s at diagnosis, and two were immunosuppressed. The tumors were located in sun-exposed areas, including the preauricular region, scalp, and cheek. Patient 2 developed lymph node metastasis, whereas the other two patients remained disease-free. In Patient 3, EMA immunostaining showed diffuse tumor-cell positivity without a ductal or luminal pattern; together with keratinizing squamous morphology and horn pearl formation, these findings favored SCC over eccrine porocarcinoma. SCC-SK should be considered in enlarging or atypical SK-like lesions, particularly in older or immunosuppressed patients.
Background:Diabetes is a chronic disease with major public health concerns and high economic costs. Effective blood sugar control is essential to delay complications caused by diabetes.Objectives:This study aims to evaluate the therapeutic potential of human dermis-derived mesenchymal stem cells (hDMSCs) in streptozotocin (STZ)-induced diabetic rats.Methods:hDMSCs were isolated from human skin and characterized by cell surface and differentiation markers. hDMSCs were induced to insulin-producing cells (IPCs), and their insulin secretion was assessed. Then, hDMSCs were transplanted into STZ-induced diabetic rats through tail vein injection. Blood glucose and glycated hemoglobin (HbA1c) levels were analyzed, and the intraperitoneal glucose tolerance test (IPGTT) was performed. After the rats were sacrificed, histological staining of the pancreas and cytokine analysis in sera were performed.Results:hDMSCs expressed CD90, CD105, and CD73 and could be differentiated into chondrocytes, osteoblasts, and adipocytes. After differentiation into IPCs, they could secrete insulin upon glucose stimulation. The transplantation of hDMSCs decreased blood glucose, HbA1c, and IPGTT metrics in STZ-induced diabetic rats compared with control rats. Histological staining showed that hDMSCs were present in the pancreases of diabetic rats, indicating that hDMSCs could localize to the pancreas after transplantation, which was associated with the presence of human insulin. Serum biochemical analysis also showed increased rat insulin and decreased proinflammatory cytokines after injection with hDMSCs.Conclusion:The administration of hDMSCs is associated with significant glycemic improvement and modulation of the inflammatory microenvironment in STZ-induced diabetic rats. While these results demonstrate the therapeutic potential of hDMSCs, further studies are required to fully elucidate the underlying mechanisms of action and long-term efficacy.
