Olov Norlén

Background: Several studies have attempted to identify the initiating drivers of small intestinal neuroendocrine tumor (SI-NET) development and the molecular mechanisms underlying their progression and metastatic spread. Previous gene expression studies have used bulk microarrays or RNA sequencing to compare tumor tissue with normal intestinal mucosa. However, the intestine comprises multiple distinct cell types, and bulk analyses are limited by this cellular heterogeneity, which can confound tumor-specific signals. Methods: We performed single-cell RNA sequencing on primary SI-NETs and paired normal mucosa from two patients to directly compare tumor cells with their cells of origin, the enterochromaffin (EC) cells. To minimize type I errors, we applied a two-step validation strategy by overlapping differentially expressed genes with an external single-cell dataset and cross-referencing candidate genes for enteroendocrine expression in the Human Protein Atlas. Results: For further distinction and characterization, ECs were subdivided into serotonergic and non-serotonergic clusters. This analysis revealed that the SI-NET cells are transcriptionally more similar to serotonergic ECs, consistent with serum metabolite profiles derived from clinical parameters. Our analyses uncovered a loss-of-expression program characterized by regulators of epithelial differentiation and in parallel, a gain-of-expression program displayed neuronal signaling gene induction, implicating functional reprogramming toward neuronal-like properties. Together, these specific losses and gains suggest that our patient-derived SI-NETs undergo adaptation through both loss of enteroendocrine functions and acquisition of neurobiological-promoting signaling pathways. Conclusions: These findings nominate candidate drivers for further functional validation and highlight potential therapeutic strategies in our patient cohort, including restoring suppressed Notch signaling and targeting aberrant neuronal signaling networks. However, even with a two-step validation procedure, the modest cohort size limits statistical power and generalizability, particularly for the proposed association to a serotonergic phenotype. Larger, multi-patient single-cell studies are required to confirm these mechanisms and establish their clinical relevance.

Purpose: Small intestinal neuroendocrine tumours (SI-NETs) are the most common malignancy of the small bowel. Curative treatment is surgical, with exploratory laparotomy considered the standard approach. This study aimed to assess the outcomes of minimally invasive surgery compared to open approach for SI-NETs at the Endocrine surgical unit at Uppsala University Hospital. Methods: This retrospective cohort study included patients who underwent surgery for SI-NET between 2013 and 2023 at Uppsala University Hospital. Variables such as operative time, length of hospital stay, use of analgesia and radicality were compared between groups of patients operated on before and after 2019, when hand-port assisted laparoscopic surgery (HALS) for SI-NETs was introduced at our unit. Outcomes were further compared between open and hand-port assisted laparoscopic approaches. The primary outcome was the rate of radicality achieved for stage II-III patients. Secondary outcomes included operative time, the length of hospital stay and the use of epidural and patient-controlled analgesia. Results: Of 97 patients, 58 (59.8%) underwent open surgery and 39 (40.2%) underwent hand-port assisted laparoscopic surgery. There was no significant difference in operative time (121 min [91.3–150.3] vs 108 min [83–141]), length of hospital stay, 6 days [4–7] vs 5 days [4–8]), and surgical radicality in patients with stage II-III, 85.2% vs 100%, (p = 0.079). 86.2% of patients with explorative laparotomy required epidural analgesia compared to only 23.1% with HALS (p < 0.001). Conclusion: Hand-port assisted laparoscopic surgery of SI-NETs is a feasible approach that preserves radical resection while enhancing postoperative recovery, with a lower requirement of epidural analgesia.

Several studies have attempted to find the initiating drivers of small intestinal neuroendocrine tumors (SI-NET) development and the molecular mechanisms driving progression and metastatic spread. For gene expression studies using bulk microarrays and RNA sequencing, researchers commonly use normal intestinal mucosa as a control. The intestine is made up of several different cell types, and using bulk RNA-seq may generate findings that reflect factors other than the tumor transformation. This could potentially contribute to the lack of discoverable treatments and prevention strategies for SI-NETs. We performed scRNA-seq on tissue from two patients that had tumor resection surgery and separated the EC cells from the normal intestinal mucosa and used specific markers to compare them against SI-NET tumors cells. We pinpointed new genes associated with chr18 haploinsufficiency but also others with loss or gain of expression that have not previously been associated with SI-NETs, and which could be potential targets for further functional genomic studies.

As part of a systematic investigation of the glycosphingolipids in human tissues, acid and non-acid glycosphingolipids from human thyroid and parathyroid glands were isolated and characterized with mass spectrometry and binding of carbohydrate-recognizing ligands, with a focus on complex compounds. The glycosphingolipid patterns of the human parathyroid and thyroid glands were very similar. The major acid glycosphingolipids were sulfatide and the gangliosides GM3, GD3, GD1a, GD1b, GT1b and Neu5Ac-neolactotetraosylceramide, and the major non-acid glycosphingolipids were globotriaosylceramide and globoside. We also found neolactotetra- and neolactohexaosylceramide, the x₂ glycosphingolipid, and complex glycosphingolipids with terminal blood group O and A determinants in both tissues. A glycosphingolipid with blood group Le^b determinant was identified in the thyroid gland, and the parathyroid sample had a glycosphingolipid with terminal blood group B determinant. Immunohistochemistry demonstrated the expression of blood group A antigens in both the thyroid and parathyroid glands. A weak cytoplasmatic expression of the GD1a ganglioside was present in the thyroid, while the parathyroid gland had a strong GD1a expression on the cell surface. Thus, the glycosylation of human thyroid and parathyroid glands is more complex than previously appreciated. Our findings provide a platform for further studies of alterations of cell surface glycosphingolipids in thyroid and parathyroid cancers.

Tumor proliferation and grade are important prognostic factors at diagnosis of PNETs. Little is known about how these factors change over time and if longitudinal increase in Ki67-index is associated with prognosis. The purpose of this work was to describe longitudinal changes in Ki67-index and tumor grade, as well as its impact on overall survival, in PNETs. Platelet free plasma from 68 GEP-NET patients was collected. Whole miRNOME NGS analysis was performed on exome enriched small-RNAs fraction of 24 patients: 12 ¹⁸PET/FDG+ and 12 ¹⁸PET/FDG-. MiRNAs significantly associated with ¹⁸PET/FDG outcome has been identified and validated by RT/qPCR on overall case series. Target miRNAs fold enrichment were then combined to create predictors (pAB, pAC, pBC and pABC). Man-Whitney test was applied and validated target miRNAs had been correlated with clinical outcome and clinical parameters (ki-67, grading, tumor burden and ⁶⁸Gallium-PET SUV_max). NGS whole miRNOME analysis revealed 10 target miRNAs able to distinguish ¹⁸FDG/PET positive from negative Pancreatic-NETs (PNETs). Subsequently, mir-A, mir-B, mir-C (patent pending) have been validated on overall case series by multiplex RT/qPCR (p < 0,0047 and p < 0,0001, respectively), on PNETs case series and pBC and pABC resulted to be the best predictors (p < 0,0001). All validated miRNAs and derived predictors, especially mir-B, result significantly increased in small intestine (SINETs) and in PNETs patients when compared to healthy controls. Correlation analysis between target miRNAs and clinical parameters also revealed that mir-B negatively correlates with ⁶⁸Ga-PET SUV_max (p < 0,04), suggesting interference with SSTR expression. We defined a 3 miRNAs signature able to correlate with ¹⁸FDG/PET status. Over expression of mir-A, mir-B, mir-C or combined predictors in PNETs can provide prognostic information on tumor aggressiveness and might help to identify PRRT non-responders. In addition mir-B negatively correlates with clinical outcome and ⁶⁸Ga-PET SUV_max. We are investigating if mirB interfere with SSTR expression, affecting PRRT efficacy. Uppsala University. European Neuroendocrine Tumor Society, Uppsala University. J. Botling: Honoraria (self): Novartis. A. Lamarca: Honoraria (self): Merck; Honoraria (self): Pfizer; Honoraria (self): Ipsen; Advisory / Consultancy: EISAI; Advisory / Consultancy: Nutricia; Travel / Accommodation / Expenses: Ipsen; Travel / Accommodation / Expenses: Pfizer; Travel / Accommodation / Expenses: Bayer; Travel / Accommodation / Expenses: AAA; Travel / Accommodation / Expenses: SirtEx; Travel / Accommodation / Expenses: Novartis; Travel / Accommodation / Expenses: Mylan; Travel / Accommodation / Expenses: Delcath. G. Rindi: Honoraria (self): Novartis; Honoraria (self): Ipsen. J. Crona: Honoraria (self): Novartis; Honoraria (self): Ipsen. All other authors have declared no conflicts of interest.

BackgroundFamilial non-medullary thyroid cancer (FNMTC) mandates family screening with ultrasound; however, the need for screening paediatric thyroid cancer with no family history has not been addressed.MethodsThis study conducted a retrospective cohort study in a tertiary hospital. The study group is composed of patients ≤18 years undergoing surgery for papillary thyroid cancer (PTC) from 2008 to 2014.ResultsDuring the study period, 15 paediatric patients had PTC. Only one patient had a prior family history of PTC involving two second-degree relatives. Of the 30 parents, four were lost to follow-up, with the remaining 26 undergoing screening thyroid ultrasound. Nodular thyroid disease was documented in eight ultrasounds performed. Subsequently, one has not undergone fine-needle biopsy, five were benign and two underwent surgical resection: one having a benign follicular adenoma and the other a papillary microcarcinoma with nodal micrometastasis.ConclusionsRoutine ultrasound screening of parents of children presenting with PTC and no family history do not demonstrate an increased incidence of FNMTC. Screening of affected families is likely to demonstrate the expected background incidence of nodular thyroid disease and incidental papillary microcarcinoma. As such, it is unlikely to be useful.

Background: A recent study of focused minimally invasive parathyroidectomy (FPTX) in sporadic primary hyperparathyroidism (pHPT) using intraoperative parathyroid hormone (ioPTH) measurements shows that inadequate ioPTH drop and multiglandular disease are more commonly found when a first gland p < 0.001). Findings at re‐operative surgery showed that the ipsilateral gland was diseased in 47 % (7/15) of persistent cases in group A.Conclusion: The risk of persistent disease after MIP was higher if the resected gland weighed ≤200 mg, and this corroborates the findings of a recent study. A heightened awareness of the possibility of multigland disease should be raised, and ioPTH monitoring, identification of the ipsilateral gland or bilateral exploration may be advisable in such cases.

Gallstone ileus is a rather rare condition and in most cases it involves a cholecysto-enteric fistula, through which a gallstone passes into the bowel. If the gallstone is large enough it may obstruct the bowel and a gallstone ileus emerges. In the presented case, the patient was subjected to a cholecystectomy over 40 years ago, but despite this, he developed a gallstone ileus. A gallstone that obstructed the small bowel was suspected with computed tomography and confirmed with exploratory laparotomy. Although a few cases of gallstone ileus after cholecystectomy are described in the literature, our case describes a unique pathogenic mechanism.