Faculty Bibliography

Eosinophilic appendicitis is a rare inflammatory condition characterized by the infiltration of eosinophils into the appendix, which is often misdiagnosed as acute appendicitis given similarities in their clinical presentation. Acute eosinophilic appendicitis: a rare cause of lower gastrointestinal hemorrhage. Within this particular report, we present a case of eosinophilic appendicitis in a 42-year-old female who underwent a laparoscopic appendectomy. The purpose of this report is to increase awareness about this unique condition and emphasize the importance of considering eosinophilic appendicitis as a differential diagnosis in patients with appendicitis-like symptoms whose clinical examination and laboratory findings may suggest otherwise.

BACKGROUND:As SARS-CoV-2 continues to be relevant and cause illnesses, the effect of emerging virus variants on perinatal health remains to be elucidated. It was demonstrated that vertical transmission of SARS-CoV-2 is a relatively rare event in the original SARS-CoV-2 strain. However, very few reports describe vertical transmission related to the delta-variant. CASE PRESENTATION/METHODS:We report a case of a preterm male neonate born to a mother with positive SARS-CoV-2 and mild respiratory complications. The neonate was born by cesarean section due to fetal distress. The rupture of the amniotic membrane was at delivery. The neonate had expected prematurity-related complications. His nasopharyngeal swabs for RT-PCR were positive from birth till three weeks of age. RT-ddPCR of the Placenta showed a high load of the SARS-CoV-2 virus with subgenomic viral RNA. RNAscope technique demonstrated both the positive strand of the S gene and the orf1ab negative strand. Detection of subgenomic RNA and the orf1ab negative strand indicats active viral replication in the placenta. CONCLUSIONS:Our report demonstrates active viral replication of the SARS-CoV-2 delta-variant in the placenta associated with vertical transmission in a preterm infant.

BACKGROUND/UNASSIGNED: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/UNASSIGNED: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/UNASSIGNED: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/UNASSIGNED: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.

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.

INTRODUCTION/BACKGROUND: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/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/CONCLUSIONS: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.

INTRODUCTION/BACKGROUND: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/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/CONCLUSIONS: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.

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 semi-allogeneic fetus, and pro-inflammatory 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 resulting from exaggerated maternal inflammatory responses to mild/moderate infections that are common during pregnancy. However, the exact mechanisms contributing to the maintenance of tolerance to repeated infections are not completely understood. miRNAs play important roles in pregnancy, with several miRNAs implicated in gestational tissue function, as well as in pathologic pregnancy conditions. miRNA-519c, a member of the C19MC cluster, is a human-specific miRNA mainly expressed in the placenta. However, its role in pregnancy is largely unknown. OBJECTIVES/OBJECTIVE: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 miRNA-519c, a placenta-specific miRNA, as a key regulator of endotoxin tolerance at the maternal-fetal interface. STUDY DESIGN/METHODS:-trimester placentas were treated with LPS. After 24 hours, the conditioned media was collected for analysis, and the placental explants were re-exposed to repeated doses of LPS for 3 days. The supernatant was analyzed for inflammatory markers, presence of extracellular vesicles (EVs) and microRNAs. To study the possible mechanism of action of the microRNAs, we evaluated the phosphodiesterase 3 B (PDE3B) pathway involved in TNF-α production using a miRNAs mimic and PDE3B siRNA 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 TNF-α and upregulated IL-10 levels. This reaction was mediated by the placenta-specific miRNA-519c packaged within placental EVs. LPS treatment increased the EVs that were positive for the exosome tetraspanin markers, namely CD9, CD63, and CD81, and secreted primarily by trophoblasts. Primary human trophoblast cells transfected with miR-519c mimic decreased PDE3B. While lack of PDE3B, achieved by siRNA transfection, resulted in a decreased TNF-α production. These data supported the hypothesis that the anti-inflammatory action of miRNA-519c was mediated by a downregulation of the phosphodiesterase 3 B pathway, leading to inhibition of TNF-α production. Furthermore, human placentas from normal and inflammation-associated pregnancies demonstrated that decreased placental miRNA-519c level was linked to infection-induced inflammatory pathologies during pregnancy. CONCLUSION/CONCLUSIONS:We identified miRNA-519c, a human placenta-specific miRNA, as a novel regulator of immune adaptation associated with infection-induced preterm birth at the maternal-fetal interface. Our study can serve as a basis for future experiments to explore the potential use of miRNA-519c as a biomarker for infection-induced preterm birth.

Although coronavirus disease 2019 (COVID-19) is transmitted via respiratory droplets, there are multiple gastrointestinal and hepatic manifestations of the disease, including abnormal liver-associated enzymes. However, there are not many published articles on the pathological findings in the liver of patients with COVID-19. We collected the clinical data from 17 autopsy cases of patients with COVID-19 including age, sex, Body mass index (BMI), liver function test (alanine aminotransaminase (ALT), aspartate aminotransaminase (AST), alkaline phosphatase (ALP), direct bilirubin, and total bilirubin), D-dimer, and anticoagulation treatment. We examined histopathologic findings in postmortem hepatic tissue, immunohistochemical (IHC) staining with antibody against COVID-19 spike protein, CD68 and CD61, and electron microscopy. We counted the number of megakaryocytes in liver sections from these COVID-19-positive cases. Abnormal liver-associated enzymes were observed in 12 of 17 cases of COVID-19 infection. With the exception of three cases that had not been tested for D-dimer, all 14 patients' D-dimer levels were increased, including the cases that received varied doses of anticoagulation treatment. Microscopically, the major findings were widespread platelet-fibrin microthrombi, steatosis, histiocytic hyperplasia in the portal tract, mild lobular inflammation, ischemic-type hepatic necrosis, and zone 3 hemorrhage. Rare megakaryocytes were found in sinusoids. COVID-19 IHC demonstrates positive staining of the histiocytes in the portal tract. Under electron microscopy, histiocyte proliferation is present in the portal tract containing lipid droplets, lysosomes, dilated ribosomal endoplasmic reticulum, microvesicular bodies, and coronavirus. The characteristic findings in the liver of patients with COVID-19 include numerous amounts of platelet-fibrin microthrombi, as well as various degrees of steatosis and histiocytic hyperplasia in the portal tract. Possible mechanisms are also discussed.