A 48-year-old woman with a history of recurrent alcoholic pancreatitis was found to have a pancreatic pseudocyst. In November 20XX, she visited the emergency department due to sudden abdominal pain. Contrast-enhanced computed tomography showed a pancreatic pseudocyst with a maximum diameter of 67 mm and ascites. A ruptured pancreatic pseudocyst was suspected and abdominal paracentesis was performed. The amylase level in the ascitic fluid was high (3444 IU/L), leading to a diagnosis of acute generalized peritonitis due to rupture of a pancreatic pseudocyst. Intraoperative findings revealed 500 mL of ascites mixed with pancreatic juice and turbid cyst contents, and distal pancreatectomy was performed. The postoperative course was favorable, and the patient was discharged on hospital day 14. Rupture of pancreatic pseudocyst is rare. In this case, it was promptly diagnosed and successfully treated with emergency surgery.

Background: Type 1 diabetes mellitus induced by immune-checkpoint inhibitors (ICI-T1DM) is a rare critical entity. However, the etiology of ICI-T1DM remains unclear. Methods: In order to elucidate risk factors for ICI-T1DM, we evaluated the clinical course and immunological status of patients with ICI-T1DM who had been diagnosed during 2016 to 2021. Results: Seven of 871 (0.8%, six men and one woman) patients developed ICI-T1DM. We revealed that the allele frequencies of human leukocyte antigen (HLA)-DPA1*02:02 and DPB1*05:01 were significantly higher in the patients with ICI-T1DM In comparison to the controls who received ICI (11/14 vs. 10/26, P=0.022; 11/14 vs. 7/26, P=0.0027, respectively). HLA-DRB1*04:05, which has been found to be a T1DM susceptibility allele in Asians, was also observed as a high-risk allele for ICI-T1DM. The significance of the HLA-DPB1*05:01 and DRB1*04:05 alleles was confirmed by an analysis of four additional patients. The absolute/relative neutrophil count, neutrophils-lymphocyte ratio, and neutrophil-eosinophil ratio increased, and the absolute lymphocyte count and absolute/relative eosinophil count decreased at the onset as compared with 6 weeks before. In two patients, alterations in cytokines and chemokines were found at the onset. Conclusion Novel high-risk HLA alleles and haplotypes were identified in ICI-T1DM, and peripheral blood factors may be utilized as biomarkers.

A 66-year-old, postmenopausal woman was referred to our hospital because of abnormal breast cancer screening results. A tumor was found in the upper outer part of the left breast. Biopsy revealed papillotubular carcinoma, ER (Allred score total score [TS] 3 = proportion score [PS] 2 + intensity score [IS] 1), PgR (Allred score TS 3 = PS 2 + IS 1), HER2 (2+), fluorescent in situ hybridization 1.1 (negative), and Ki-67 labeling index 15%. In diagnostic imaging, the tumor size was 35 mm. The diagnosis was T2N0M0 Stage IIA, luminal B-like breast cancer. First, letrozole 2.5 mg/day was administered as preoperative hormone therapy. After 2 months of treatment with letrozole, the tumor size had increased to 44 mm and preoperative hormone therapy was discontinued. She was started on preoperative chemotherapy (4 courses of epirubicin plus cyclophsphamide followed by 4 courses of triweekly docetaxel). The tumor size decreased, becoming undetectable. After these preoperative treatments, nipple-sparing mastectomy, sentinel lymph node biopsy, and breast reconstruction with a primary latissimus dorsi flap were performed. As of 3 years and 6 months after the operation, there has been no recurrence. At first, preoperative hormone therapy is performed for Luminal B-like breast cancer as in this case, if the response is insufficient, preoperative chemotherapy after hormone therapy may be a therapeutic option.

Primary mesenteric neuroendocrine tumor is extremely rare. Here we describe 2 cases of this disease. Case 1 was a 66-year-old man with a working diagnosis of gastrointestinal stromal tumor or mesenteric tumor who underwent laparoscopic tumor resection. Immunohistochemically, the final diagnosis was primary mesenteric neuroendocrine tumor G1. There has been no recurrence as of 25 months after surgery. Case 2 was an 80-year-old man with a working diagnosis of gastrointestinal stromal tumor or mesenteric tumor who also underwent laparoscopic tumor resection. Immunohistochemically, the final diagnosis was primary mesenteric neuroendocrine tumor G1. This is recurrence-free as of 36 months after surgery. Several cases of primary mesenteric neuroendocrine tumor have been reported, but most have been treated with open surgery. To date, there has been only 1 case of primary mesenteric NET that was resected in a pure laparoscopic procedure. In all 3 cases (including our 2 cases), the largest tumor diameter was 4 cm. It appears that laparoscopic surgery can be used to treat primary mesenteric neuroendocrine tumor of small size (＜ 4 cm) with minimal invasion.

Here, we report 3 cases of conservatively treated ischemic colitis with hepatic portal venous gas. In Case 1, an 84-year-old man visited the emergency department because of fatigue, vomiting, and upper abdominal pain. In Case 2, a 72-year-old man was hospitalized for rehabilitation in another hospital following cervical spine trauma. He had diarrhea and mesogastric pain for 2 days and was transferred to our hospital. In Case 3, an 89-year-old woman visited the emergency department because of upper abdominal pain and vomiting. In all cases, we diagnosed the illness as ischemic colitis with hepatic portal venous gas based on computed tomography findings, and the vital signs of all patients were stable. They were treated conservatively. They were able to resume oral intake and were discharged or transferred to another hospital. Hepatic portal venous gas has been considered a poor prognostic sign of severe diseases such as intestinal necrosis. However, recently, reports of cases treated conservatively have been increasing. Conservative treatment may be selected for ischemic colitis associated with hepatic portal venous gas taking into account the patient’s general condition.