Yoshinobu Akasaka

Communicating bronchopulmonary foregut malformation: particular emphasis on concomitant congenital tracheobronchial stenosis

A total of four patients with communicating bronchopulmonary foregut malformation were treated surgically at Kobe Children’s Hospital between 1993 and 2004. Of these, three patients displayed congenital tracheobronchial stenosis and developed life-threatening respiratory distress soon after birth. In each case, anomalous bronchi arose from the lower portion of the esophagus and connected to the lower part of the ipsilateral lung. This anomaly involved the right lung in two patients, and the left lung in one patient. Tracheobronchial stenosis extended from the inlet of the thorax to the carina in one patient, and to the contralateral main stem bronchus in two patients. Surgical treatment included division of the esophageal bronchus and anastomosis of bronchus to the trachea in one patient. In the other patient, the ipsilateral lung was resected and the stenotic tracheobronchus was stented. The remaining patient underwent pneumonectomy of the ipsilateral lung. Details of this fatal anomaly and a discussion of appropriate surgical management are described herein.

A new approach to risk stratification using fetal MRI to predict outcomes in congenital diaphragmatic hernia: the preliminary retrospective single institutional study

Background Congenital diaphragmatic hernia (CDH) is a condition with a wide range of severity. Prenatal diagnosis is essential to optimize postnatal management, especially for severe cases. The lung to head ratio (LHR) and liver herniation estimated by prenatal ultrasound has been used as prenatal predictors in CDH. However, reliability of these factors remains to be proven and prediction of outcome from prenatal imaging is still challenging. We propose our new stratification system using lung to liver signal intensity ratio (LLSIR) in fetal MRI, which has been shown to be related to pulmonary maturation. Methods Retrospective chart review was conducted on 25 infants with CDH treated from 2009 through 2016 in our hospital. We stratified patients according to fetal T2-weighted MRI as Grade I, detectable ipsilateral lung at the apex; Grade II, undetectable ipsilateral lung at the apex and contralateral LLSR ≥2.0; Grade III, undetectable ipsilateral lung at the apex and contralateral LLSR <2.0. To evaluate this stratification system, we analyzed survival, severity [inhaled nitric oxide (iNO) usage with or without extracorporeal membrane oxygenation (ECMO)], and requirement of patch closure. Results All 15 patients survived in Grade I, while 2 out of 6 died in Grade II, and 3 out of 4 died in Grade III (P=0.003). Four were severe in Grade I, and all in Grade II and III who survived (P=0.007). One needed patch in Grade I, and all in Grade II and III (OR: 414,238,332; 95% CI, 0-∞). Liver herniation was noted in five patients, and significantly associated with survival (P=0.04), however, neither with severity (P=1.00) nor with the requirement of patch closure (P=0.52). Conclusions The risk stratification algorithm using contralateral LLSIR in fetal MRI could be useful and more reliable than liver herniation to predict survival, severity, and need of patch closure. Further investigation is warranted.

Congenital mesoblastic nephroma with focal anaplastic lesion

To the Editor: Congenital mesoblastic nephroma (CMN) is a rare renal tumor that comprises spindle cells and most often arises in newborns and infants. CMNs are classified into three types: cellular, classic, and mixed type. Cellular type CMN expresses the same chimeric protein ETV6-NTRK3 as does infantile fibrosarcoma and is therefore regarded as infantile fibrosarcoma within the kidney. Pathologically, cellular type CMN is sometimes difficult to distinguish from clear cell sarcoma of the kidney (CCSK) because CCSK is also a childhood, renal, mesenchymal tumor. However, differentiating cellular type CMN from CCSK is clinically important because therapy after nephrectomy and prognosis differ greatly between these cancers. CCSKs display several variations of histological patterns, and an anaplastic pattern is seen in approximately 2.6% of primary and recurrent CCSKs. To our knowledge, no cellular type CMN or infantile fibrosarcoma with an anaplastic pattern has been reported. Here, we describe a renal spindle cell tumor with focal anaplastic lesion in a pediatric patient. The presence of focal anaplastic lesion made diagnosis of CMN difficult, and verifying expression of the oncogenic ETV6-NTRK3 fusion was the key to accurately diagnosing cellular type CMN. This case demonstrates that focal anaplastic lesion may be seen in cellular type CMN. The patient was a boy aged one year and five months. His family noticed abdominal enlargement when he was 1 year old, but did not consider the condition serious because his abdomen was soft and he was afebrile and not vomiting. However, his abdomen gradually became harder and more enlarged. He was admitted to our hospital at the age of 1 year and 5 months. A right renal tumor measuring 9 × 12 cm with necrosis was found on abdominal enhanced computed tomography. No distant metastasis, lymphadenopathy, or tumor infiltration into the inferior vena cava was detected. Right nephrectomy was performed. The right kidney was resected with the right ureter and right adrenal gland; this complex weighed 1.1 kg and measured 15 × 12 × 12 cm. No rupture of the capsule was evident. On cut section, the tumor was soft and displayed variegated color with the dark red of hemorrhage and the brown of necrosis in the center and a white-yellow color at the margins. The tumor was fairly well demarcated. Samples for reverse transcriptase-polymerase chain reaction (RT-PCR) were taken from the white-yellow peripheral part of the tumor. On microscopic examination, the tumor margin was sharply and linearly demarcated or had infiltrated only a short distance into the renal parenchyma with a pushing border. The tumor was within the kidney and had not invaded into the renal capsule. No invasion into the renal pelvis or adipose tissue in the renal sinus was found. The cut ends of the ureter and the renal artery and vein were tumor-negative. An old hematoma and wide necrosis were centered within the tumor, and microscopic necrotic foci were scattered within the tumor. The tumor entrapped isolated renal tubules or glomeruli. The tumor comprised interlacing fascicles of spindle cells with bipolar cytoplasmic processes and round to slightly elongated nuclei containing fine chromatin and a few (1 or 2) tiny nucleoli (Fig. 1a). A storiform pattern of cells was observed. Mitotic counts per one high-power field (HPF) were 1 to 7 (mean approximately 4), but karyorrhexis was more frequent than mitosis. Cells with bizarre giant nuclei or with multiple nuclei and with abundant eosinophilic cytoplasm were found in the sharply demarcated nodular region that measured 4 × 2 mm (Fig. 1b). Multipolar mitotic figures were also observed in this region. So these cells fulfill the criteria of anaplasia defined for nephroblastoma, CCSK, and anaplastic sarcoma of the kidney (ASK). There were no transitional features between the anaplastic lesion and the surrounding