Satohiko Yanagisawa

Identification and Metastatic Potential of Tumor-Initiating Cells in Malignant Rhabdoid Tumor of the Kidney

Purpose: Malignant rhabdoid tumor of the kidney (MRTK) is a rare and highly aggressive malignancy of infanthood. In an effort to delineate MRTK progression, we investigated the metastatic fate of some MRTK cells using xenotransplantation animal models and the tumor-initiating potential of CD133+ MRTK cells. Experimental Design: We established two MRTK cell lines (JMU-RTK-1 and JMU-RTK-2) from patients with MRTK. We generated five luciferase-expressing MRTK cells for in vivo luminescent imaging and evaluated the metastatic fate in an orthotopic xenotransplantation model. Capacities of MRTK-initiating cells were examined in nonobese diabetic/severe combined immunodeficient mice after antibody-mediated magnetic bead sorting. Use of chemokine receptor CXCR4 expression as a metastatic marker was evaluated by flow cytometry and Western blotting. Results: MRTK cell lines showed distant organ metastasis. JMU-RTK-1, JMU-RTK-2, and G401 cells showed considerable aggressiveness compared with SWT-1 and SWT-2 cells (P < 0.05). Moreover, as few as 1,000 CD133+ MRTK cells initiated tumor development in nonobese diabetic/severe combined immunodeficient mice by 21 days (60-100%) in all examined cell lines, although the same number of CD133− MRTK cells could not form tumors (0%). Interestingly, the metastatic potential of the CD133+ population remained unaffected compared with a nonenriched population. The potential metastatic marker CXCR4 was expressed in CD133+ and CD133− MRTK cells, and CD133− cells seemed to play a cooperative role in terms of tumorigenicity and metastasis. Conclusions: These results suggest that CD133+ cells may determine the metastatic fate of MRTK cells and that CD133− cells may play an auxiliary role in tumor progression and metastasis.

A new operative strategy for refractory microcystic lymphangioma

The optimal management of microcystic lymphatic malformations (LMs) in children has not been established. We describe how we used the Ligasure™ Vessel Sealing System (LVSS) to achieve partial resection of refractory microcystic LMs in a 1-year-old boy. The child was admitted in respiratory distress caused by infection and swelling of cervical LMs. The LMs had been diagnosed prenatally, but had not decreased in size despite three treatments with OK-432 sclerotherapy. We performed direct dissection of the microcystic LMs using the LVSS with minimal intraoperative blood loss or lymphatic leakage. The LMs were resected as completely as possible without damage to the jugular vein or major nerves. His postoperative course was uneventful. Histological examination revealed complete sealing of the lymphovascular channels with obliterated lumens. Resection using the LVSS is effective and easy to perform for partial resection of microcystic LMs. We recommend the combination of initial OK-432 injection therapy and subsequent partial resection using the LVSS for refractory microcystic LMs.

A novel diagnostic and treatment strategy for small intestinal lesions in children: hybrid treatment using transumbilical minimal incision surgery combined with double-balloon enteroscopy

IntroductionDouble-balloon enteroscopy (DBE) is a useful and feasible modality for evaluating small intestinal lesions, even in children.MethodsDBE makes it possible to perform biopsy, diagnosis, polypectomy and endoscopic therapies including hemostasis, tattooing and clipping of the small intestinal lesions. However, endoscopic procedures in the small intestines of children are more difficult than in adults, because the intestinal wall is thin and the lumen is narrow. A novel hybrid treatment was developed using DBE for small bowel lesions combined with transumbilical minimal incision surgery.ConclusionThis hybrid treatment is safe, effective, provides excellent cosmetic results and can be used as an alternative for traditional open laparotomy or endoscopic surgery.

Mesenchymal hamartoma of the bilateral chest wall in neonates

A mesenchymal hamartoma of the chest wall is a rare benign tumor. Each case has a different clinical course as well as different radiological imaging findings, and various histopathological diagnoses. In addition, mesenchymal hamartoma is sometimes mistaken for a malignant tumor. This report presents a neonatal case of mesenchymal hamartoma of the bilateral chest wall.

Intrapericardial extralobar pulmonary sequestration detected as an intrathoracic cystic mass by using prenatal ultrasonography: Case report and review of the literature

Intrapericardial extralobar pulmonary sequestration is a very rare congenital lung anomaly. We report a case of this condition, detected as an intrathoracic cystic lesion by using prenatal ultrasonography. The neonate was born at 38 weeks of gestation with no progression of the lesion and no respiratory or cardiac symptoms. Ultrasonography and computed tomography (CT) revealed a 40 × 17 × 17-mm intrapericardial lesion, composed of cystic components and a solid component. Intrapericardial extrapulmonary sequestration was suspected largely because CT showed a vague aberrant artery. At the age of 3 months, elective surgery was performed, and the postoperative course was uneventful.

Do neonates conceived after assisted reproductive technology require neonatal surgery more frequently? A 5‐year single‐center experience

Assisted reproductive technology (ART) has increased the incidences of multiple gestations and low birth weights, which frequently warrant pediatric surgery. ART may have also increased the rate of birth defects. In this study, we aimed to determine whether infants conceived after ART required neonatal surgery more frequently compared with naturally conceived infants.

A new paradigm of scarless abdominal surgery in children: Transumbilical minimal incision surgery

PURPOSE This study aimed to evaluate the use of a transumbilical incision for infants and children, as well as neonates, with various intraabdominal conditions. METHODS A retrospective study of transumbilical incision surgery was performed between June 2007 and June 2013. Patients were divided into two groups: group 1 of neonates and group 2 of infants and children. All operations were performed via an upper circumumbilical incision. RESULTS Thirty-six patients (22 males, 14 females) were treated via a transumbilical incision, with 20 patients in group 1 and 16 patients in group 2. A transverse incision extension was needed for 1 case in group 1 (intestinal atresia complicated by meconium peritonitis) and 4 cases in group 2 (two with ileus owing to adhesive bands, 1 with malrotation, 1 with ectopic pancreatic tissue in the duodenum). In cases with a dilated intestinal wall or intraabdominal adhesions, an optional extension of the transverse incision might be required. Only 1 case with ileus in group 2 developed a wound infection that was treated by drainage. The postoperative cosmetic results were acceptable in all cases. CONCLUSION The transumbilical incision yielded a sufficiently large surgical field, and the surgical condition was easily and directly viewed. In all 36 cases, an adequate operation was safely performed. This approach is a safe and effective method for various intraabdominal disorders in not only neonates but also infants and children, and leads to an imperceptible incision.