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Esophageal perforations are associated with a high morbidity and mortality in the pediatric population. Most cases are managed conservatively with antibiotics, nutritional supplementation, and percutaneous drainage of fluid collections. Direct surgical repair is reserved for patients with hemodynamic instability or evidence of clinical worsening due to the high risk of postoperative complications. Utilization of stents in the treatment of acute esophageal perforation has become well-established in adults, but evidence remains lacking in the pediatric population. We present the case of a 4-year old male with an acute esophageal perforation who was successfully treated with an esophageal self-expanding metal stent (SEMS) in lieu of direct surgical repair. He failed extubation on postoperative day (POD) 6 due to tracheal compression by the oversized stent but exhibited good healing with successful extubation on POD 13. This case report demonstrates that esophageal stents may be a promising alternative to surgical repair in the pediatric population. Further studies and trials should be performed to compare the effectiveness of esophageal stenting to direct surgical repair. Modification and downsizing of the adult SEMS design for pediatric anatomy is recommended to prevent complications such as tracheal compression and prolonged intubation.

Non-firearm abdominal impalement is a rare presentation of pediatric trauma and presents unique challenges. Here, we present the case of a 13-year-old girl who sustained transabdominal impalement of a tree branch from a sledding accident in which she was being towed behind an ATV. Complicating her care was a concurrent, city-wide state of emergency in which internet and cellular communications were impaired after the bombing of a communication building. To characterize trajectory, computer tomographic (CT) scan imaging showed the branch traversed the right retroperitoneum, obstructing the ureter and inferior vena cava, passed adjacent to the inferior wall of the 4th portion of the duodenum, perforated the stomach, and exited the peritoneum through the left abdominal wall musculature. Laparotomy identified lacerations to the anterior and posterior gastric walls, a duodenal laceration, and significant debris throughout the abdomen. Three visceral defects were closed primarily. A contrast study on POD5 confirmed integrity of the repairs. She recovered well and was discharged on POD13. This case highlights the importance of evaluating patient-specific mechanism of injury (“look at”), assessing patients in real time when provider communications are limited due to any disaster (“look up”), and sharing with the community critical public health lessons (“look around”).

Wilms tumor (WT) blastema retains gene expression profiles characteristic of the multipotent nephron progenitor pool, or cap mesenchyme (CM), in the developing kidney. As a result, WT blastema and the CM are believed to represent contextual analogues of one another. Sine oculis homeobox 2 (SIX2) is a transcription factor expressed specifically in the CM, provides a critical mechanism for CM self-renewal, and remains persistently active in WT blastema, although its purpose in this childhood malignancy remains unclear. We hypothesized that SIX2, analogous to its function in development, confers a survival pathway to blastema, the putative WT stem cell. To test its functional significance in WT biology, wild-type SIX2 was overexpressed in the human WT cell line, WiT49. After validating this model, SIX2 effects on anchorage-independent growth, proliferation, invasiveness, canonical WNT pathway signaling, and gene expression of specific WNT pathway participants were evaluated. Relative to controls, WiT49 cells overexpressing SIX2 showed significantly enhanced anchorage-independent growth and early-passage proliferation representing surrogates of cell survival. Interestingly, overexpression of SIX2 generally repressed TCF/LEF-dependent canonical WNT signaling, which activates and coordinates both differentiation and stem pathways, but significantly heightened canonical WNT signaling through the survivin promoter, a mechanism that exclusively maintains the stem state. In summary, when overexpressed in a human WT cell line, SIX2 enhances cell survival and appears to shift the balance in WNT/β-catenin signaling away from a differentiation path and toward a stem cell survival path.

Hepatoblastoma, the most common pediatric liver cancer, consists of epithelial mixed embryonal/fetal (EMEF) and pure fetal histologic subtypes, with the latter exhibiting a more favorable prognosis. Few embryonal histology markers that yield insight into the biologic basis for this prognostic discrepancy exist. CBP/P-300 interacting transactivator 1 (CITED1), a transcriptional co-activator, is expressed in the self-renewing nephron progenitor population of the developing kidney and broadly in its malignant analog, Wilms tumor (WT). In this current study, CITED1 expression is detected in mouse embryonic liver initially on post-coitum day 10.5 (e10.5), begins to taper by e14.5, and is undetectable in e18.5 and adult livers. CITED1 expression is detected in regenerating murine hepatocytes following liver injury by partial hepatectomy and 3,5-diethoxycarbonyl-1,4-dihydrocollidine. Importantly, while CITED1 is undetectable in normal human adult livers, 36 of 41 (87.8%) hepatoblastoma specimens express CITED1, where it is enriched in EMEF specimens compared to specimens of pure fetal histology. CITED1 overexpression in Hep293TT human hepatoblastoma cells induces cellular proliferation and upregulates the Wnt inhibitors Kringle containing transmembrane protein 1 (KREMEN1) and CXXC finger protein 4 (CXXC4). CITED1 mRNA expression correlates with expression of CXXC4 and KREMEN1 in clinical hepatoblastoma specimens. These data show that CITED1 is expressed during a defined time course of liver development and is no longer expressed in the adult liver but is upregulated in regenerating hepatocytes following liver injury. Moreover, as in WT, this embryonic marker is reexpressed in hepatoblastoma and correlates with embryonal histology. These findings identify CITED1 as a novel marker of hepatic progenitor cells that is re-expressed following liver injury and in embryonic liver tumors.

The application of minimally invasive surgery (MIS) to resect pediatric solid tumors offers the potential for reduced postoperative morbidity with smaller wounds, less pain, fewer surgical site infections, decreased blood loss, shorter hospital stays, and less disruption to treatment regimens. However, significant controversy surrounds the question of whether a high-fidelity oncologic resection of childhood cancers can be achieved through MIS. This review outlines the diverse applications of MIS to treat pediatric malignancies, up to and including definitive resection. This work further summarizes the current evidence supporting the efficacy of MIS to accomplish a definitive, oncologic resection as well as appropriate patient selection criteria for the minimally invasive approach.

Wilms' tumors, or nephroblastomas, are thought to arise from abnormal postnatal retention and dysregulated differentiation of nephrogenic progenitor cells that originate as a condensed metanephric mesenchyme within embryonic kidneys. We have previously shown that the transcriptional regulator CITED1 (CBP/p300-interacting transactivators with glutamic acid [E]/aspartic acid [D]-rich C-terminal domain) is expressed exclusively in these nephrogenic progenitor cells and is downregulated as they differentiate to form nephronic epithelia. In the current study, we show that CITED1 expression persists in blastemal cell populations of both experimental rat nephroblastomas and human Wilms' tumors, and that primary human Wilms' tumors presenting with disseminated disease show the highest level of CITED1 expression. Unlike the predominantly cytoplasmic subcellular localization of CITED1 in the normal developing kidney, CITED1 is clearly detectable in the nuclear compartment of Wilms' tumor blastema. These findings indicate that CITED1 is a marker of primitive blastema in Wilms' tumors and suggest that persistent expression and/or altered subcellular localization of CITED1 in the condensed metanephric mesenchyme could play a role in Wilms' tumor initiation and pathogenesis.