Objective Early presentation and prompt diagnosis of acute appendicitis are necessary to prevent progression of disease leading to complicated appendicitis. We hypothesize that patients had a delayed presentation of acute appendicitis during the COVID-19 pandemic, which affected severity of disease on presentation and outcomes. Patients and methods We conducted a retrospective review of all patients who were treated for acute appendicitis at Morgan Stanley Children's Hospital (MSCH) between March 1, 2020 and May 31, 2020 when the COVID-19 pandemic was at its peak in New York City (NYC). For comparison, we reviewed patients treated from March 1, 2019 to May 31, 2019, prior to the pandemic. Demographics and baseline patient characteristics were analyzed for potential confounding variables. Outcomes were collected and grouped into those quantifying severity of illness on presentation to our ED, type of treatment, and associated post-treatment outcomes. Fisher's Exact Test and Kruskal-Wallis Test were used for univariate analysis while cox regression with calculation of hazard ratios was used for multivariate analysis. Results A total of 89 patients were included in this study, 41 patients were treated for appendicitis from March 1 to May 31 of 2019 (non-pandemic) and 48 were treated during the same time period in 2020 (pandemic). Duration of symptoms prior to presentation to the ED was significantly longer in patients treated in 2020, with a median of 2 days compared to 1 day (p = 0.003). Additionally, these patients were more likely to present with reported fever (52.1% vs 24.4%, p = 0.009) and had a higher heart rate on presentation with a median of 101 beats per minute (bpm) compared to 91 bpm (p = 0.040). Findings of complicated appendicitis on radiographic imaging including suspicion of perforation (41.7% vs 9.8%, p < 0.001) and intra-abdominal abscess (27.1% vs 7.3%, p = 0.025) were higher in patients presenting in 2020. Patients treated during the pandemic had higher rates of non-operative treatment (25.0% vs 7.3%, p = 0.044) requiring increased antibiotic use and image-guided percutaneous drain placement. They also had longer hospital length of stay by a median of 1 day (p = 0.001) and longer duration until symptom resolution by a median of 1 day (p = 0.004). Type of treatment was not a predictor of LOS (HR = 0.565, 95% CI = 0.357–0.894, p = 0.015) or duration until symptom resolution (HR = 0.630, 95% CI = 0.405–0.979, p = 0.040). Conclusion Patients treated for acute appendicitis at our children's hospital during the peak of the COVID-19 pandemic presented with more severe disease and experienced suboptimal outcomes compared to those who presented during the same time period in 2019. Level of Evidence III

The Notch pathway plays multiple key roles in tumorigenesis, and its signaling components have therefore aroused great interest as targets for emerging therapies. Here we show that inhibition of Notch, using a soluble receptor Notch1 decoy, unexpectedly caused a remarkable increase in liver metastases from neuroblastoma and breast cancer cells. Increased liver metastases were also seen after treatment with the γ-secretase inhibitor PF-03084014. Transgenic mice with heterozygous loss of Notch1 demonstrated a marked increase in hepatic metastases, indicating that Notch1 signaling acts as metastatic suppressor in the liver microenvironment. Inhibition of DLL1/4 with ligand-specific Notch1 decoys increased sprouting of sinusoidal endothelial cells into micrometastases, thereby supporting early metastatic angiogenic growth. Inhibition of tumor-derived JAG1 signaling activated hepatic stellate cells, increasing their recruitment to vasculature of micrometastases, thereby supporting progression to macrometastases. These results demonstrate that inhibition of Notch causes pathological activation of liver stromal cells, promoting angiogenesis and growth of hepatic metastases. Our findings have potentially serious implications for Notch inhibition therapy.

Vascular endothelial growth factor

We describe the clinical course of a recurrent case of congenital fibrosarcoma diagnosed in a 9-mo-old boy with a history of hemimelia. Following complete surgical resection of the primary tumor, the patient subsequently presented with bulky bilateral pulmonary metastases 6 mo following surgery. Molecular characterization of the tumor revealed the absence of the prototypical ETV6-NTRK3 translocation. However, tumor characterization incorporating cytogenetic, array comparative genomic hybridization, and RNA sequencing analyses, revealed a somatic t(2;15)(2p21;15q25) translocation resulting in the novel fusion of EML4 with NTRK3. Cloning and expression of EML4-NTRK3 in murine fibroblast NIH 3T3 cells revealed a potent tumorigenic phenotype as assessed in vitro and in vivo. These results demonstrate that multiple fusion partners targeting NTRK3 can contribute to the development of congenital fibrosarcoma.