Enhanced Complement Expression in the Tumor Microenvironment Following Neoadjuvant Therapy: Implications for Immunomodulation and Survival in Pancreatic Ductal Adenocarcinoma.

Background: Neoadjuvant therapy (NAT) is increasingly being used for pancreatic ductal adenocarcinoma (PDAC) treatment. However, its specific effects on carcinoma cells and the tumor microenvironment (TME) are not fully understood. This study aims to investigate how NAT differentially impacts PDAC's carcinoma cells and TME. Methods: Spatial transcriptomics was used to compare gene expression profiles in carcinoma cells and the TME between 23 NAT-treated and 13 NAT-naïve PDAC patients, correlating with their clinicopathologic features. Analysis of an online single-nucleus RNA sequencing (snRNA-seq) dataset was performed for validation of the specific cell types responsible for NAT-induced gene expression alterations. Results: NAT not only induces apoptosis and inhibits proliferation in carcinoma cells but also significantly remodels the TME. Notably, NAT induces a coordinated upregulation of multiple key complement genes (C3, C1S, C1R, C4B and C7) in the TME, making the complement pathway one of the most significantly affected pathways by NAT. Patients with higher TME complement expression following NAT exhibit improved overall survival. These patients also exhibit increased immunomodulatory and neurotrophic cancer-associated fibroblasts (CAFs); more CD4+ T cells, monocytes, and mast cells; and reduced immune exhaustion gene expression. snRNA-seq analysis demonstrates C3 complement was specifically upregulated in CAFs but not in other stroma cell types. Conclusions: NAT can enhance complement production and signaling within the TME, which is associated with reduced immunosuppression in PDAC. These findings suggest that local complement dynamics could serve as a novel biomarker for prognosis, evaluating treatment response and resistance, and guiding therapeutic strategies in NAT-treated PDAC patients.

Thyroid Metastasis to the Colon.

Approximately 1% of colorectal cancers can be attributed to metastatic neoplasms originating from other primary sources typically the lung, ovary, breast, prostate, kidney, or skin. Metastasis to the colon from the thyroid however is exceedingly rare. We present a 76-year-old man with a history of papillary thyroid carcinoma WHO presented with colon polyps consistent with carcinoma from his papillary thyroid carcinoma. The findings in this report suggest prompt colorectal cancer screening after thyroid cancer diagnosis and regular screening thereafter.

Improving fine needle aspiration to predict the tumor biological aggressiveness in pancreatic neuroendocrine tumors using Ki-67 proliferation index, phosphorylated histone H3 (PHH3), and BCL-2.

INTRODUCTION: Surgery is the only known cure for sporadic pancreatic neuroendocrine tumors (PNETs). Therefore, the prediction of the PNETs biological aggressiveness evaluated on endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) has a significant impact on clinical management. The proliferation rate of Ki-67 in PNETs can help to predict the biological aggressiveness of the tumor. In addition, there is a relatively new proliferation marker called phosphorylated histone H3 (PHH3) that can identify and quantify dividing cells in tissue samples, which is a marker highly specific to mitotic figures. Other markers such as BCL-2 also contribute to tumorigenesis and may be involved in the differentiation of neuroendocrine cells. MATERIALS AND METHODS: A retrospective observational study was performed on patients undergoing surveillance for PNETs from January 2010 to May 2021. Data collection included the patients' age, sex, tumor location, tumor size in the surgical specimen, and tumor grade in FNA. The 2019 World Health Organization (WHO) classification guideline was followed to diagnose PNETs, including grade and stage. Immunohistochemical stainings for Ki-67, PHH3 and BCL-2 in PNETs were performed. RESULTS: After excluding cell blocks containing fewer than 100 tumor cells, 44 patients with EUS-FNA and surgical resection specimens were included in this study. There were 19 cases of G1 PNETs, 20 cases of G2 PNETs, and 5 cases of G3 PNETs. The grade assigned based on the Ki-67 index was higher and more sensitive than that based on the mitotic count using H&E slides in some cases of G2 and G3 PNETs. However, there was no significant difference between the mitotic count using PHH3-positive tumor cells and the Ki-67 index to grade PNETs. All grade 1 tumors (19 cases) on surgical resection specimens were correctly graded on FNA (100 % concordance rate). Within the 20 G2 PNETs, 15 cases of grade 2 on surgical resection specimens were graded correctly on FNA based on the Ki-67 index only. Five cases of grade 2 PNETs on surgical resection specimens were graded as grade 1 on FNA when using only the Ki-67 index. Three of five grade 3 tumors on surgical resection specimens were graded as grade 2 on FNA based on the Ki-67 index only. Using only FNA Ki-67 to predict PNET tumor grade, the concordance (accuracy) rate was 81.8 % in total. However, all these eight cases (5 cases of G2 PNETs and 3 cases of G3 PNETs) were graded correctly by using the Ki-67 index plus mitotic rate (using PHH3 IHC stains). Four of 18 (22.2 %) patients with PNETs were positive for BCL-2 stain. In these 4 cases positive for BCL-2 stains, 3 cases were G2 PNETs and one case was G3 PNETs. CONCLUSION: Grade and the proliferative rate in EUS-FNA can be used to predict the tumor grade in surgical resection specimens. However, when using only FNA Ki-67 to predict PNET tumor grade, about 18 % of cases were downgraded by one level. To solve the problem, immunohistochemical staining for BCL-2 and especially PHH3 would be helpful. Our results demonstrated that the mitotic count using PHH3 IHC stains not only improved the accuracy and precision of PNET grading in the surgical resection specimens, but also could reliably be used in routine scoring of mitotic figures of FNA specimens.

The concordance between wide-area transepithelial sampling with computer-assisted 3-dimensional analysis (WATS-3D) and standard endoscope biopsy in the detection of Barrett's esophagus and esophageal dysplasia.

INTRODUCTION: Barrett's esophagus (BE) is a premalignant condition that leads to susceptibility to developing adenocarcinoma. The most common endoscopic surveillance technique is forceps biopsy, which involves sampling the specimen every 1 to 2 cm along the length of the lesion. This technique has a low sensitivity and often leaves the majority of the esophageal mucosa untested. Recently, the use of wide-area transepithelial sampling with computer-assisted 3-dimensional analysis (WATS-3D) has received much attention. However, there is little known about this novel technique, and this research aims to add to our knowledge of WATS-3D by comparing it to traditional forceps biopsy. MATERIALS AND METHODS: A retrospective observational study was performed. All existing GI biopsy cases diagnosed with WATS-3D were identified from the institutional pathology databases of NYU Langone Hospital - Long Island from 2019 to 2021. Data collection included patients' age, sex, and dysplasia results. Existing pathology reports and CDx diagnostics were reviewed. All the existing slides of the biopsy cases were pulled out and reviewed. Dysplasia was classified as no dysplasia, indefinite for dysplasia, lowgrade dysplasia, and high-grade dysplasia. RESULTS: A total of 109 cases were included in this study. There are 59 cases diagnosed as BE with forceps biopsy, 72 cases by WATS-3D, and 77 cases by WATS-3D combined with forceps biopsy. The sensitivity of detecting BE was significantly increased by WATS-3D and further by WATS-3D combined with forceps biopsy. In 59 cases diagnosed as BE with forceps biopsy, 50 cases were classified as no dysplasia, 3 cases were indefinite for dysplasia, 5 cases were low-grade dysplasia, and 1 case was high-grade dysplasia. In 72 cases diagnosed as BE by WATS-3D, 64 cases were classified as no dysplasia, 7 cases were indefinite for dysplasia, 1 case was high-grade dysplasia, and no cases with low-grade dysplasia. In 77 cases diagnosed as BE by WATS-3D combined with forceps biopsy, 63 cases were classified as no dysplasia, 8 cases were indefinite for dysplasia, 5 cases with low-grade dysplasia, and 1 case was highgrade dysplasia. The maximal longitudinal extent of the esophageal mucosal changes strongly correlated with the severity of BE. CONCLUSION: Compared to traditional forceps biopsy, WATS-3D was more sensitive in finding intestinal metaplasia. However, WATS-3D could not clearly discriminate low-grade dysplasia from indefinite for dysplasia and tended to classify low-grade dysplasia as indefinite for dysplasia. The addition of WATS-3D to forceps biopsy resulted in an increase in diagnostic yield and thus an increase in the quality of patient care.

Placental extracellular vesicles-associated microRNA-519c mediates endotoxin adaptation in pregnancy.

BACKGROUND: Pregnancy represents a unique challenge for the maternal-fetal immune interface, requiring a balance between immunosuppression, which is essential for the maintenance of a semiallogeneic fetus, and proinflammatory host defense to protect the maternal-fetal interface from invading organisms. Adaptation to repeated inflammatory stimuli (endotoxin tolerance) may be critical in preventing inflammation-induced preterm birth caused by exaggerated maternal inflammatory responses to mild or moderate infections that are common during pregnancy. However, the exact mechanisms contributing to the maintenance of tolerance to repeated infections are not completely understood. MicroRNAs play important roles in pregnancy with several microRNAs implicated in gestational tissue function and in pathologic pregnancy conditions. MicroRNA-519c, a member of the chromosome 19 microRNA cluster, is a human-specific microRNA mainly expressed in the placenta. However, its role in pregnancy is largely unknown. OBJECTIVE: This study aimed to explore the role of "endotoxin tolerance" failure in the pathogenesis of an exaggerated inflammatory response often seen in inflammation-mediated preterm birth. In this study, we investigated the role of microRNA-519c, a placenta-specific microRNA, as a key regulator of endotoxin tolerance at the maternal-fetal interface. STUDY DESIGN: Using a placental explant culture system, samples from term and second-trimester placentas were treated with lipopolysaccharide. After 24 hours, the conditioned media were collected for analysis, and the placental explants were re-exposed to repeated doses of lipopolysaccharide for 3 days. The supernatant was analyzed for inflammatory markers, the presence of extracellular vesicles, and microRNAs. To study the possible mechanism of action of the microRNAs, we evaluated the phosphodiesterase 3B pathway involved in tumor necrosis factor alpha production using a microRNA mimic and phosphodiesterase 3B small interfering RNA transfection. Finally, we analyzed human placental samples from different gestational ages and from women affected by inflammation-associated pregnancies. RESULTS: Our data showed that repeated exposure of the human placenta to endotoxin challenges induced a tolerant phenotype characterized by decreased tumor necrosis factor alpha and up-regulated interleukin-10 levels. This reaction was mediated by the placenta-specific microRNA-519c packaged within placental extracellular vesicles. Lipopolysaccharide treatment increased the extracellular vesicles that were positive for the exosome tetraspanin markers, namely CD9, CD63, and CD81, and secreted primarily by trophoblasts. Primary human trophoblast cells transfected with a microRNA-519c mimic decreased phosphodiesterase 3B, whereas a lack of phosphodiesterase 3B, achieved by small interfering RNA transfection, led to decreased tumor necrosis factor alpha production. These data support the hypothesis that the anti-inflammatory action of microRNA-519c was mediated by a down-regulation of the phosphodiesterase 3B pathway, leading to inhibition of tumor necrosis factor alpha production. Furthermore, human placentas from normal and inflammation-associated pregnancies demonstrated that a decreased placental microRNA-519c level was linked to infection-induced inflammatory pathologies during pregnancy. CONCLUSION: We identified microRNA-519c, a human placenta-specific microRNA, as a novel regulator of immune adaptation associated with infection-induced preterm birth at the maternal-fetal interface. Our study serves as a basis for future experiments to explore the potential use of microRNA-519c as a biomarker for infection-induced preterm birth.

Cholesterol Crystal Embolization to the Kidney and to a Duodenal Leiomyoma.

Cholesterol crystal embolism can be spontaneous or iatrogenic, and it can involve any organ of the gastrointestinal tract, presenting with common gastrointestinal symptoms such as bleeding, perforation, obstruction, and inflammation. It is therefore considered the "great masquerader," requiring a high level of suspicion because the condition is associated with increased morbidity and mortality. We present a 69-year-old man who presented with gastrointestinal bleeding and azotemia. He was found to have cholesterol crystal embolization in the kidney and a duodenal leiomyoma, the latter being an uncommon site to embolize.

Sporadic ganglioneuromatosis of esophagogastric junction in a patient with gastro-esophageal reflux disorder and intestinal metaplasia.

A 58-year-old female with a recurrent history of upper abdominal pain and intermittent dysphagia underwent endoscopic evaluation that demonstrated an irregular and nodular esophago-gastric (EG) junction and grade I erosive esophagitis. Biopsies showed prominent intestinal metaplasia of Barrett's type without dysplasia, chronic inflammation and multiple aggregates of large cells within the mucosal lamina propria, some with spindle shaped nuclei. Immunohistochemistry stains for keratins AE-1/AE-3 were negative, while S-100 and NSE were positive. This, together with routine stains, was diagnostic for mucosal ganglioneuromatosis. The background of chronic inflammation with intestinal type metaplasia was consistent with long-term reflux esophagitis. No evidence of achalasia was seen. Biopsies of gastric antrum and fundus were unremarkable, without ganglioneural proliferation. Colonoscopy was unremarkable. No genetic syndromes were identified in the patient including familial adenomatous polyposis and multiple endocrine neoplasia type IIb (MEN IIb). Iansoprazole (Prevacid) was started by oral administration each day with partial relief of symptoms. Subsequent esophagogastroscopy repeated at 4 mo showed normal appearing EG junction. Esophageal manometry revealed a mild non-specific lower esophageal motility disorder. Mild motor dysfunction is seen with gastro-esophageal reflux disease (GERD) and we feel that the demonstration of localized ganglioneuromatosis was not likely related etiologically. In the absence of findings that might suggest neural hypertrophy, such as achalasia, the nodular mucosal irregularity seen with this instance of ganglioneuromatosis may, however, have exacerbated the patient's reflux.