The aim of this study was to evaluate the features of pulmonary histopathological changes in cases of trisomy 18 complicated with congenital heart disease and pulmonary arterial hypertension. Twenty‐eight patients with trisomy 18 underwent open lung biopsy at the time of primary operation in our hospital between 2008 and 2019. We compared these histopathological findings with those from previously described groups without trisomy 18. Mean age at primary cardiac surgery was 37 days (range, 9–69 days). According to the Heath‐Edwards (HE) classification, 1, 8, 12, and 5 patients were graded as 0, 1, 2, and 3, respectively, whereas 2 patients were not classifiable due to medial defects in the small pulmonary arteries (MD). Four (14.3%) and 13 (46.4%) patients presented with MD and hypoplasia of the small pulmonary arteries (HS). Fifteen (53.6%) and 21 (75.0%) patients presented with alveolar hypoplasia (AH) and alveolar wall thickening (AT). MD, HS, and AH in trisomy 18 were present frequently, differing significantly from previous reports. These findings might be associated with congenital inadequate development of vessels and alveoli in the lung, contributing to a high risk of PAH in trisomy 18.

We present a case of a healthy 7-month-old female infant who developed sudden le heart failure due to acute mitral regurgitation (MR). She was rushed to our hospital on the day of onset and underwent semiemergency surgery the next day. Antimicrobial treatment was initiated upon admission, and pyrexia occurred 8 h later. At surgery, the anatomical ndings included the destruction of both the anterior and posterior lea ets of the mitral valve, posterior mitral valve lea et perforation, an undetected rupture of the chordae tendineae, and no vegetation on the mitral valve. Mitral valve replacement was performed because of the di culty of mitral valve annuloplasty. A culture test of blood and resected anterior mitral valve demonstrated no bacterial or fungal infection, but histopathological analysis revealed polymorphonuclear cell in ltration of the resected mitral valve lea et.e patient was diagnosed with infective endocarditis (IE) based on these ndings; however, we were unable to determine the cause of infection or pathogenic bacteria. Acute MR in infants can be caused by IE and acute rupture of the chordae tendineae of the mitral valve (RCTMV). e current case of infantile IE started with acute MR due to signi cant valvular destruction, followed by pyrexia, and progressed quickly, similar to RCTMV in infants. Because the treatment and complications of acute MR in healthy infants are dependent on the cause, we must take special care to ascertain the cause along with histopathological analysis.Keywords: acute mitral regurgitation, infective endocarditis, mitral valve perforation, acute rupture of the chordae tendineae of the mitral valve in infants

Transient abnormal myelopoiesis (TAM) can cause early death in children with Down syndrome, and liver failure is the most common cause of death. The aim of this singlecenter retrospective study was to identify a quantitative index for predicting TAM-related mortality at the time of diagnosis. Of the 462 children with Down syndrome admitted to our hospital from 1992 to 2021, we studied 12 infants with TAM-related death and 31 survivors who were diagnosed with TAM. In the death and survival groups, the median gestational ages were 34.9 and 37.1 weeks, respectively (p = 0.12). At diagnosis, the white blood cell (WBC) counts were 99.2 and 36.2 × 10 9 /L (p = 0.011), the hemoglobin concentrations were 131 and 159 g/L (p = 0.009), and the serum albumin concentrations were 23 and 31 g/L (p < 0.001), respectively. The areas under the receiver operating characteristic curve for the abilities of the WBC count, hemoglobin, and serum albumin at diagnosis to predict survival were 0.75, 0.76, and 0.85, respectively. The serum albumin concentration threshold of 28 g/L at diagnosis had sensitivity of 0.79 and specificity of 0.82. Gestational age and serum albumin concentration were entered into a logistic regression model. The serum albumin concentration was an independent indicator of TAM-related death (adjusted odds ratio, 0.78; 95% confidence interval, 0.65-0.93; p = 0.005). In conclusion, a low serum albumin concentration at diagnosis may be a good predictor of TAM-related death.