Introduction: Duodenal gastrointestinal stromal tumours (GIST) are rare. Therefore, difficulties are experienced when selecting the appropriate surgical procedure in patients with duodenal GISTs. This report presents the cases of three patients with duodenal GISTs who underwent wedge resection. This report would help surgeons identify clinical features and surgical procedures in patients with duodenal GISTs. Presentation of case: Three patients were diagnosed with duodenal submucosal tumours. The first patient presented with melena, the second with postoperative anaemia, and the third with an incidental finding of a large abdominal tumour after presenting with ischaemic colitis. All tumours arose in the 2nd portion of the duodenum and measured 3.5, 3, and 9.2 cm, respectively. Wedge resection of the duodenum was performed in all patients. In patients one and two, simple closure of duodenal wall was performed after wedge resection. In patient three, side-to-side anastomosis with the jejunum was performed because a large area of the wall was removed using the wedge resection technique. Pancreatoduodenectomy was avoided in all patients. Recurrence was not noted in any patient. Discussion: Since GISTs are not generally associated with lymph node metastasis, local resection with negative margins is sufficient to surgically manage patients with GISTs. Conclusion: Our results indicated the effectiveness of performing wedge resection for duodenal GISTs not in close proximity to the ampulla of Vater. Moreover, less invasive procedures should be adopted in patients with duodenal GISTs. Highlights:

Pancreatic ductal adenocarcinoma (PDAC) is a lethal malignancy with limited treatment options, and early detection remains challenging due to the lack of reliable non-invasive biomarkers. This study investigated plasma and urine circulating tumor deoxyribonucleic acid (ctDNA) methylation profiles as potential biomarkers for PDAC detection. A total of 35 patients with PDAC and 10 non-cancerous controls were enrolled, and whole-genome bisulfite sequencing was performed on ctDNA extracted from both plasma and urine samples. Plasma ctDNA methylation profiles effectively distinguished cancerous from non-cancerous samples, particularly through differential methylation in intergenic regions. Hierarchical clustering further enabled the accurate grouping of patients with PDAC. However, urine ctDNA did not show significant methylation differences. These findings suggest that plasma ctDNA methylation holds promise as a non-invasive biomarker for PDAC detection, whereas urine ctDNA appears less informative. Future research should validate these findings in larger cohorts and investigate machine learning approaches to improve diagnostic performance, ultimately facilitating earlier detection and improved patient outcomes.

Background Olaparib is effective in the treatment of metastatic breast cancer (MBC) patients, mainly confirmed by deleterious germline BRCA mutations. However, real-world data are scarce. Methodology A total of 10 cases from our institute and 17 cases from the relevant Japanese literature were reviewed. All 27 patients had MBC with confirmed deleterious germline BRCA mutations. Tumor reduction, response duration, disease-free interval (DFI), overall survival (OS), and safety were assessed. Additionally, exploratory research was conducted on the characteristics of a subgroup of patients who had a long-term response to olaparib. Results In the 10 cases from two Juntendo hospitals who received olaparib from July 2018 to December 2021, the median age was 48 years (range = 37-63 years). The same numbers of BRCA1 and BRCA2 mutations and the same ratios of luminal and triple negative (TN) breast cancer cases were observed. The metastatic sites, mainly visceral, included the lungs (n = 4), liver (n = 5), and bone (n = 6). The median duration of drug use was four months (range = 1-36 months). The median number of treatment regimens from metastasis to olaparib administration was 2.0 (range = 1-9 regimens). The median DFI was 21 months (range = 0-106 months). The median OS was not reached (range = 16-191 months). In the subgroup analysis of six cases in which olaparib was effective for four months or more, there was a case where DFI was longer than 100 months. Treatment-related toxicities (TRTs) included neutropenia (n = 5; 50%), anemia (n = 4; 40%), thrombocytopenia (n = 2; 20%), nausea (n = 1; 10%), and fatigue (n = 1; 10%). CTCAE (version 5.0) grade ≥3 TRTs included anemia (n = 1; 10%) and neutropenia (n = 5; 50%). On the other hand, neutropenia was previously said to be as low as 27.3%, lower than anemia (40.0%), in a population including various races. We additionally examined another 17 cases from the Japanese literature. Conclusions To our knowledge, this study reports the first real-world data of Japanese patients with MBC and confirmed deleterious germline BRCA mutations. Our data showed that olaparib is effective in the real world. The incidence of neutropenia seemed higher in Japanese patients.

Introduction: Anatomical variations in the arterial supply to the right colon are clinically relevant in patients undergoing laparoscopic and robotic colectomy, as misidentification of the vessels may lead to inadequate lymphadenectomy or bowel ischemia. A common trunk formed by the ileocolic artery (ICA) and middle colic artery (MCA), arising from the superior mesenteric artery (SMA), is an uncommon vascular configuration that may complicate surgical decision-making. Presentation of case: A 73-year-old man presented with constipation and abdominal pain. Colonoscopy revealed a circumferential type 2 tumor in the ascending colon, causing luminal stenosis. Histopathological examination of a biopsy confirmed moderately differentiated adenocarcinoma. Using contrast-enhanced computed tomography, wall thickening without distant metastasis was detected. Three-dimensional computed tomography angiography revealed a rare vascular anomaly in which the ICA and MCA originated from a common trunk arising from the SMA, accompanied by the absence of the right colic artery. The patient underwent an elective robot-assisted right hemicolectomy using the da Vinci Si® system. The postoperative course was uneventful; the patient was discharged on postoperative day 8. The pathological diagnosis was pT3N0M0, stage IIa adenocarcinoma. No recurrence has been observed during the 3-year follow-up. Discussion: Preoperative three-dimensional vascular imaging is useful for identifying uncommon vascular variants and translating findings into a safe intraoperative strategy. The robotic approach allows precise vascular handling in such cases. Conclusions: Awareness of such anatomical configurations may help prevent intraoperative misinterpretation and support meticulous preoperative planning, particularly in minimally invasive and robotic right colectomy.

INTRODUCTION: Phyllodes tumors of the breast are rare fibroepithelial neoplasms accounting for 0.3%–1.0% of all primary breast tumors. They are classified into benign, borderline, and malignant subtypes, with borderline and malignant tumors associated with an increased risk of local recurrence and distant metastasis. Giant phyllodes tumors, defined as tumors larger than 10 cm in diameter, are uncommon, and reports of tumors exceeding 20 cm are extremely rare. We report a case of a rapidly growing giant benign phyllodes tumor with skin ulceration, along with a review of the relevant literature.CASE PRESENTATION: A 48-year-old Asian woman presented with rapid enlargement of the left breast and active bleeding from an ulcerated mass. Clinical findings and imaging studies revealed a well-circumscribed giant tumor measuring 24 cm that occupied the entire left breast, without evidence of distant metastasis. Core needle biopsy suggested a fibroepithelial tumor, and a benign phyllodes tumor was most strongly considered. A left mastectomy was performed. Skin grafting had been considered preoperatively, as the skin defect would be large. However, as sufficient skin flaps were obtained intraoperatively, due to the skin being stretched by the tumor, only mastectomy was done without a reconstructive procedure. Histopathological examination confirmed a benign phyllodes tumor with negative surgical margins. The postoperative course was uneventful.CONCLUSIONS: We experienced a rare case of a giant breast tumor and tumor resection. Although rapid breast tumor growth and skin breakdown suggested malignancy, the pathological diagnosis was a benign phyllodes tumor. This highlights the importance of considering phyllodes tumors in the differential diagnosis of rapidly enlarging breast masses and the need for timely surgical intervention. This case is particularly noteworthy because it demonstrates an unusual combination of clinical features—giant tumor size, rapid growth, and skin ulceration—that are generally associated with malignant disease, despite the final diagnosis being benign.