Unifocal versus Multiple Ileal Neuroendocrine Tumors Location: An Embryological Origin

Abstract

<b><i>Introduction:</i></b> Small-intestinal neuroendocrine tumors (SI-NET) are situated preferentially within the ileum. The aim was to describe a potential difference in location between unifocal and multiple ileal-NET. <b><i>Patients and Methods:</i></b> Between December 2010 and December 2019, all consecutive patients who underwent resection in our European Neuroendocrine Tumor Society Center of Excellence, of at least 1 non-duodenal SI-NET, were retrospectively included. The main objective was to prove that multiple ileal-NET were mostly located on the left side of the superior mesenteric artery (SMA) axis (defined as 40 cm from the ileocecal valve), and unifocal ones on the right side. <b><i>Results:</i></b> Ninety-four patients were included, 6 with unifocal jejunal-NET located 35 cm (range, 10–60) from the duodenojejunal angle (DJA), 44 (47%) with unifocal ileal-NET and 44 (47%) with multiple ileal-NET. The median number of tumors in multiple ileal-NET was 7 (range, 2–95), within a median small bowel segment of 105 cm (10–240). The median length between the proximal tumor and the DJA was 428 cm (300–635) and 540 cm (350–725) for the distal one; 40 (91%) of them were located on the left side of the SMA axis. In contrast, unifocal ileal-NET were located at a median distance of 577 cm (305–820) from the DJA (<i>p</i> < 0.001, compared to multiple ileal-NET); 30 (68%) of them were on the right side of the SMA axis (<i>p</i> < 0.001). <b><i>Conclusion:</i></b> Multiple ileal-NET are mostly located on the left side of the SMA axis. Further studies are warranted to explore the embryological origin of unifocal versus multiple ileal-NET.

Multifocal neuroendocrine tumour of the small bowel presenting as an incarcerated incisional hernia: a surgical challenge in a high-risk patient

“…All patients with localised SBNET with or without mesenteric lymph node metastases, and those with resectable liver metastases should be considered for surgery with an intent to eliminate macroscopic disease [ 9 ]. Meticulous abdominal exploration and palpation of the entire small intestine are pivotal since preoperative imaging understages the disease in up to 70% of cases [ 3 , 10 ] and in up to 50%, multiple primaries can be found [ 11 ]. Resection of primary tumour/s follows the principles of intestinal sparing surgery by avoiding extensive en-bloc resections, preserving the proximal portion of the superior mesenteric artery and vein, and thus minimizing the risk of postoperative short bowel syndrome [ 12 ].…”

Keeping Cell Death Alive: An Introduction into the French Cell Death Research Network

“…This suggests that Netrin-3 could represent a therapeutic vulnerability for SCLC. Much work remains to be done to understand the molecular mechanisms and clinical implications of axonal guidance factors in cancer and resistance to treatment via cell death blockade in particular in neuroendocrine tumors [ 70 , 71 ].…”

Subtypes and proliferation patterns of small intestine neuroendocrine tumors revealed by single cell RNA sequencing

“…The majority of SiNETs are low grade well-differentiated tumors, usually diagnosed at advanced stages and often present with metastases and stage IV tumor, highlighting their high metastatic potential [3]. Interestingly, SiNETs are often multifocal, with a common finding of synchronous multiple primaries along the small intestine [4,5]. Two recent studies demonstrated that synchronous SiNETs primaries within the same individual usually do not share somatic alterations, indicating that they arise from different cell clones [6,7].…”