Background: Gastric hamartomatous inverted polyp (GHIP) is a pathological condition where enlarged gastric glands with cystic dilatation grow in the submucosa. It is difficult to excise the tissue due to its location. In addition, even if the tissue is taken correctly, making an accurate diagnosis is difficult due to foveolar epithelium in the tissue, which can be misdiagnosed as gastric mucosal epithelium. Thus, an accurate diagnosis of GHIP is rarely established from a biopsy alone preoperatively. We here report a case of GHIP with a central dimple, which was diagnosed and treated using a modified combination of laparoscopic and endoscopic approaches to neoplasia with a non-exposure technique (modified CLEAN-NET). Case presentation: A 60-year-old man with a submucosal tumor (SMT) in the stomach was referred to our hospital by a primary care doctor. On examination, a gastrointestinal stromal tumor was suspected. Modified CLEAN-NET was performed for diagnostic and therapeutic purposes. The histopathological examination of the resected specimen showed an enlarged gland duct in the submucosal layer. This finding, along with immunostaining results, led to the diagnosis of GHIP. The postoperative course was uneventful without any symptoms. Conclusions: GHIP should be considered among the differential diagnoses of SMT of the stomach. Modified CLEAN-NET may be beneficial in the removal of SMTs such as GHIP with a central dimple because it can avoid stomach deformation of the stomach and tumor dissemination.

In order to develop a biomarker predicting the efficacy of treatments for patients with esophageal squamous cell carcinoma (ESCC), we evaluated the subpopulation of T cells in ESCC patients treated with chemotherapy (CT), chemoradiotherapy (CRT), and nivolumab therapy (NT). Fifty-five ESCC patients were enrolled in this study, and peripheral blood samples were collected before and after CT or CRT and during NT. Frequencies of memory, differentiated, and exhausted T cells were evaluated using flow cytometry among cStages, treatment strategies, pathological responses of CT/CRT, and during NT. The frequencies of PD-1+ or TIM-3+CD4+ T cells were significantly higher in patients with cStage IV. PD-1+CD4+ and TIM-3+CD8+ T-cell populations were significantly higher in patients treated with CRT but were not associated with treatment response. The frequencies of both CD4+ and CD8+ CD45RA−CD27+CD127+ central memory T cells (TCM) were significantly decreased during the course of NT in the progressive disease group. Taken together, the alteration in frequency of CD45RA−CD27+CD127+ TCM during NT may be a biomarker to predict its therapeutic response in ESCC patients.

The cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway plays a crucial role in activating immune cells in the tumor microenvironment, thereby contributing to a more favorable response to immune checkpoint inhibitors (ICI) in colorectal cancer (CRC). However, the impact of the expression of cGAS-STING in tumor cells on the infiltration of CD8+ T cells and clinical outcomes in mismatch repair proficient/microsatellite stable (pMMR/MSS) CRC remains largely unknown. Our findings reveal that 56.8% of all pMMR CRC cases were cGAS-negative/STING-negative expressions (cGAS−/STING−) in tumor cells, whereas only 9.9% of all pMMR CRC showed cGAS-positive/STING-positive expression (cGAS+/STING+) in tumor cells. The frequency of cGAS+/STING+ cases was reduced in the advanced stages of pMMR/MSS CRC, and histone methylation might be involved in the down-regulation of STING expression in tumor cells. Since the expression level of cGAS-STING in tumor cells has been associated with the infiltration of CD8+ and/or CD4+ T cells and the frequency of recurrence in pMMR/MSS CRC, decreased expression of cGAS-STING in tumor cells might lead to poor immune cell infiltration and worse prognosis in most pMMR/MSS CRC patients. Our current findings provide a novel insight for the treatment of patients with pMMR/MSS CRC.