Purpose: To provide recommendations for the diagnosis and treatment of pyriform sinus fistula (PSF) in the fetus and neonate through a systematic review of the published literature. Methods: PubMed and Embase (1968-2019) were searched, and additional publications were obtained by searching the references by hand. The two reviewers assessed all papers and extracted the following variables: demographics, clinical features, diagnostic tests, interventions, and prognoses. Results: Forty-two papers were included, comprising a total of 158 cases. PSF presented almost exclusively on the left side (95.56%). Patients usually presented with a neck mass (100%) and respiratory distress (43.18%). The false-negative rate (FNR) of prenatal ultrasonography (US) was significantly higher than that of prenatal magnetic resonance imaging (MRI) (P < 0.01). For the diagnosis of PSF in neonates, computerized tomography (CT) and MRI were the most accurate diagnostic modalities. Ex utero intrapartum treatment (EXIT) was performed during delivery in 6 patients (26.09%). Among 135 patients with a reported date of definitive surgery, 117 (86.67%) underwent surgery during the neonatal period. Complications after definitive surgery appeared in 5 patients (3.16%), and all of them recovered spontaneously within 3 months. Furthermore, recurrence occurred in 4 patients (2.53%). Conclusion: In fetal cases with PSF suspected by US, MRI is necessary to confirm the diagnosis. During the neonatal period, patients with PSF typically present with a neck mass and respiratory distress, and CT/MRI appears to be the preferred diagnostic method. Definitive surgery is effective for treating neonatal PSF, with a low complication rate and low recurrence rate.

Acute acalculous cholecystitis (AAC) is the inflammatory disease of the gallbladder in the absence of gallstones. AAC is estimated to represent at least 50% to 70% of all cases of acute cholecystitis during childhood. Although this pathology was originally described in critically ill or post-surgical patients, most pediatric cases have been observed during several infectious diseases. In addition to cases caused by bacterial and parasitic infections, most pediatric reports after 2000 described children developing AAC during viral illnesses (such as Epstein-Barr virus and hepatitis A virus infections). Moreover, some pediatric cases have been associated with several underlying chronic diseases and, in particular, with immune-mediated disorders. Here, we review the epidemiological aspects of pediatric AAC, and we discuss etiology, pathophysiology and clinical management, according to the cases reported in the medical literature.

Acute acalculous cholecystitis (AAC) is a rare complication of infectious mononucleosis (IM). An immunocompetent 6-year-old Japanese girl complained of epigastralgia during the course of IM. Ultrasonography (US) revealed a markedly thickened and sonolucent gallbladder wall. No gallstones were apparent. Antibodies against Epstein-Barr virus (EBV) confirmed primary EBV infection. Cytomegalovirus immunoglobulin M showed a false-positive result in the acute phase, probably due to cross-reaction to EBV nuclear antigen. We diagnosed her as AAC related with primary EBV infection. She recovered completely by conservative treatment. US should be performed in consideration of the possibility of AAC when a patient with IM complains of epigastralgia.

Acute acalculous cholecystitis (AAC) is an inflammation of the gallbladder, which does not appear to be associated with the presence of gallstones. AAC is estimated to represent more than 50% of cases of acute cholecystitis in the pediatric population. Although this pathology was initially described in critically ill patients, actually most pediatric cases have been observed during several infectious diseases. Particularly, here we reviewed pediatric infectious acute acalculous cholecystitis and analyzed the pathophysiological and clinical aspects of bacterial and viral forms.