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Aims: This study investigated the relationship between the differentiation of tumour cells into crypts, which is determined by cell differentiation into Paneth and neuroendocrine cells, and tumour infiltration in gastric dysplasia. Methods and results: The lesions were endoscopically biopsied low‐grade dysplasia (LGD), endoscopically resected high‐grade dysplasia (HGD) or cancer with submucosal invasion. LGD (n = 32) displayed crypt differentiation across the entire width of the tumour in all cases. Crypt differentiation was identified as a characteristic of tumours with low biological malignancy. HGD (n = 40) included tumours with a mixture of areas with and without crypt differentiation (n = 25) and tumours with crypt differentiation throughout the entire width (n = 15). Of the cancers with submucosal invasion (n = 30), the morphological progression of the HGD area with crypt differentiation, the HGD area without crypt differentiation and invasive cancer without crypt differentiation was confirmed for 23 samples. In two lesions, invasive cancer without crypt differentiation developed from HGD without crypt differentiation throughout the tumour width. In five samples, well‐differentiated tubular adenocarcinoma with crypt differentiation developed from HGD with crypt differentiation and invaded with lamina propria‐like stroma. Conclusions: Loss of crypt differentiation could be an objective indicator of infiltration in the progression of HGD to invasive cancer. The invasive potential of dysplasia depends upon the presence or absence of crypt differentiation. [ABSTRACT FROM AUTHOR]

Pancreatic cancer is a malignant neoplasm with high invasiveness and poor prognosis. In a previous study, a highly invasive pancreatic cancer cell line was established and found to feature enhanced interleukin-32 (IL-32) expression. However, whether IL-32 promotes the invasiveness by enhancing or suppressing the expression of IL-32 through regulating downstream molecules was unclear. To investigate the effect of IL-32, cells were established with high levels of expression or downregulated IL-32; their invasive ability was measured using a real-time measurement system and the expression of some candidate downstream molecules involved in invasion was evaluated in the two cell types. The morphological changes in both cell types and the localization of IL-32 expression in pancreatic cancer tissues were studied using immunohistochemistry. Among the several splice variants of IL-32, cells transfected with the ε isoform had increased invasiveness, whereas the IL-32-suppressed cells had reduced invasiveness. Several downstream molecules, whose expression was changed in the two cell types, were monitored. Notably, changes of E-cadherin, CLDN1, CD44, CTGF and Wnt were documented. The morphologies of the two cell types differed from the original cell line. Immunohistochemically, the expression of IL-32 was observed only in tumor cells and not in normal pancreatic cells. In conclusion, IL-32 was found to promote the invasiveness of pancreatic cancer cells by regulating downstream molecules. [ABSTRACT FROM AUTHOR]

Alveolar rhabdomyosarcoma (ARMS) is a malignant tumor with skeletal muscle differentiation that usually occurs in soft tissues of the extremities or trunk. To date, only a few cases of primary gastric ARMS have been reported. Herein, we describe a case of ARMS in a man in his 80s and present a literature review. A submucosal tumor-like lesion was detected endoscopically. Histologically, the tumor cells exhibited a poorly differentiated morphology with hyperchromatic nuclei. Neuroendocrine markers, such as synaptophysin and CD56, were positive, and neuroendocrine carcinoma (NEC) was considered a differential diagnosis. However, both myogenic markers and OLIG2, which reflect FAX3 or FAX7 fusion, were positive, leading to a diagnosis of ARMS. Primary gastric ARMS is an extremely rare condition. Better awareness of this entity and its similarity to NEC is necessary for appropriate diagnosis and treatment., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Okuno et al.)