Small Intestinal Carcinoma

SBAs display genomic heterogeneity. The novel HGC stratifies these tumors based on homology to foregut or hindgut alterations and may be superior to anatomic location for characterizing pathology. Additional studies are needed to validate and further explore these findings.

It underscores the importance of maintaining diagnostic vigilance in patients with hereditary cancer syndromes and supports an aggressive, multidisciplinary approach, including neoadjuvant therapy, even in cases initially presumed to represent locally advanced PDAC. Recognition of such atypical presentations is essential not only for optimising management but also for reinforcing the central role of tumour biology in guiding diagnosis, therapeutic decision-making, and future research in hereditary malignancies.

The postoperative course was uneventful, with no recurrence on follow-up. This case highlights ileal perineurioma as a rare but important differential diagnosis in adult small-bowel intussusception, with definitive diagnosis reliant on histopathological and immunohistochemical evaluation.

P1, N=30, Active, not recruiting, City of Hope Medical Center | Trial completion date: Jun 2026 --> May 2027

Multivariate analysis showed that a distance from the lesion center to the ligament of Treitz of 85 mg/L (OR=6.168, 95%CI: 1.514-25.128, P=0.007) were independent risk factors for PPOI after segmental jejunal resection. Patients undergoing proximal jejunal resection, defined as a distance from the lesion center to the ligament of Treitz of <30 cm, as well as those with postoperative hypokalemia and elevated C-reactive protein levels, are at a higher risk of developing PPOI.

P=N/A, N=36, Recruiting, Dartmouth-Hitchcock Medical Center | Trial completion date: Dec 2026 --> Dec 2027 | Trial primary completion date: Sep 2026 --> Sep 2027

P2, N=54, Recruiting, Yale University | Initiation date: Mar 2026 --> Jun 2026

We present a renal transplant recipient with metastatic small bowel adenocarcinoma harboring a POLE mutation who was treated with pembrolizumab and achieved a complete metabolic response on PET-CT with negative circulating tumor DNA. This case suggests that immune checkpoint inhibitors may be considered in carefully selected transplant recipients with high tumor mutational burden, though risks remain.

Gross examination of the colectomy specimen revealed more than 20 large polyps measuring up to 4 cm. Histopathological analysis demonstrated colonic serrated polyposis without evidence of invasive malignancy, wall infiltration, or lymph node involvement, with clear surgical margins.

The patient recovered uneventfully with resolution of bleeding and normalization of hemoglobin. This case highlights the importance of considering small bowel GIST in unexplained melena and severe anemia and demonstrates the curative potential of timely surgical resection in localized low-risk disease.

P=N/A, N=750, Active, not recruiting, M.D. Anderson Cancer Center | Trial completion date: Jan 2026 --> Jan 2028 | Trial primary completion date: Jan 2026 --> Jan 2028

This case highlights an unusual presentation of a rare malignancy in a duodenal neuroendocrine tumor identified during evaluation of iron deficiency anemia. It emphasizes the importance of comprehensive endoscopic assessment and targeted biopsy in patients with unexplained anemia, including consideration of uncommon gastrointestinal neoplasms.