Abnormal distribution of enteric nerves such as adrenergic, cholinergic and non-adrenergic non-cholinergic nerves (NANC) may cause the failure of relaxation at the involved bowel segment in Hirschsprung's disease (HD). Nitric oxide (NO) is a major inhibitory NANC neurotransmitter in the gastrointestinal tract. NO is synthesized by activation of nNOS (neuronal nitric oxide synthase) in the intramural ganglion cells and regulates bowel movement. To assess the distribution of nNOS in HD, immunohistochemical staining to nNOS was utilized on paraffin embedded specimens. Ten control colon specimens were tested for feasibility of staining. Immunohistochemisrty was done on ganglionic colon as well as aganglionic segment of 15 patients with HD. nNOS immunoreactivity was observed in the neuronal cells, small cells and nerve fibers in the muscle layer and submucosal neuronal cells of control specimens. This finding was also observed in the ganglionic segments of HD. But, there was no nNOS immunoreactivity in aganglionic segments of HD. In conclusion nNOS immunohistochemical staining of paraffin embedded specimen is feasible and reliable. And the results suggest that the relaxation failure of the aganglionic bowel in HD is related to the absence of nNOS containing cells and nerve fibers.

Mesenchymal hamartoma of the liver is a rare benign tumor, usually presenting in early childhood. Five children with mesenchymal hamartoma of the liver pathologically verified at Seoul National University Children's Hospital between 1978 and 2000 were analyzed retrospectively. There were two girls and three boys, and their mean age at the operation was 16.0months (range, 4 - 32 months). Three patients presented with abdominal distension. A patient was detected incidentally, and another was detected by prenatal ultrasongraphic examination. Tumor size ranged from 10x8.5cm to 34x29cm. Three tumors were located in the right lobe and two in the left lobe. Four cases underwent complete surgical resection, and the other one underwent incomplete surgical resection and marsupialization. Recurrence or malignant transformation was not noted. Five patients survived without evidence of disease for 35, 36, 38, 142 and 228 months. In conclusion, although mesenchymal hamartoma of the liver is benign lesion, it may be confused, and mixed with embryonal sarcoma. A recent report showed recurrence or malignant transformation after partial excision of the tumor. Therefore, complete excision of the tumor with surrounding normal liver tissue is recommended.

Ventriculoperitoneal shunt (VP shunt) for hydrocephalus is thought to inhibit the closure of processus vaginalis by increasing intraabdominal pressure, thus it promotes the inguinal hernia. We reviewed the incidence and characteristics of the inguinal hernia in VP shunted patients, and tried to estimate the patency rate of processus vaginalis in early childhood. A reprospective review of patients undergone insertion of VP shunt between January 1980 and May 1998 at Seoul National University Children Hospital was done. 262 patients were included in this study. Among them, 28 patients developed inguinal hernia (10.7%). Six patients developed inguinal hernia before the insertion of VP shunt. According to the age of VP shunt, the inguinal hernia developed in 16.2% (12/74) of patients who had undergone VP shunt before 6 months old, 12.4% (11/89) between 6 months and 2 years old and 5.1% (5/99) after 2 years old. Among 22 patients excluding 6 patients who developed hernia before VP shunt, the incidence of inguinal hernia after VP shunt was 8.6% (22/256) with male predominance (M:F=18:4). 8 patients developed inguinal hernia bilaterally (36.4%). It is suggested that at least 14% of processus vaginalis is patent until 2 years old.

Spontaneous rupture of the eventrated diaphragm is not common. The authors report a case of spontaneous rupture of the congenital diaphragmatic eventration. An 8 year-old girl with right congenital diaphragmatic eventration and nephrotic syndrome was seen in emergency room because of severe abdominal pain and vomiting. She had intermittent abdominal pain for 1 year. Plain chest X-ray and ultrasonography showed entrapped bowels in the right thoracic area. Exploratory laparotomy revealed a ruptured right eventration. THE displaced abdominal viscera were repositioned into the abdominal cavity and the ruptured diaphragm was trimmed and plicated. The postoperative course was uneventful. Only one case of spontaneous rupture of eventrated diaphragmatic has been reported in the English literature.

The WDHA syndrome characterized by watery diarrhea, hypokalemia, and achlorhydria (WDHA syndrome) is rare, and with neurogenic tumors. A 20-month-old girl presenting with symptoms of WDHA syndrome was transferred to our hospital. She had a ganglioneuroblastoma of the adrenal gland. The serum level of VIP was elevated. After complete excision of the tumor, all symptoms related to the WDHA syndrome were relieved and serum VIP level dropped to normal. The postoperative course was uneventful. The patient was treated with postoperative chemotherapy and radiation therapy. There was no evidence of disease 33 months after operation.

Fecal incontinence is not rare in post-op. children who had anorectal malformation, Hirschsprung's disease, and meningomyelocele. It can negatively impact the patient's emotional and social development. Among the options, antegrade continence enema (ACE) was introduced to overcome the demerits in 9 cases from January 1998 to June 1999. All patients have meningomyelocele. The cleanliness and post-operative complications were evaluated. The operative technique has three categories including reversed appendicocecostomy, in situ appendicostomy and neoappendicostomy with cecal flap. All of the patients achieved complete cleanliness. Four patients had post-operative complications. There were two patients with stoma leakage, one with abdominal pain on irrigation and one with stoma stenosis. The leakage was minimal and the pain on irrigation improved spontaneously. The stoma stenosis required revision operation on post-operative 6th month. The ACE has been shown to be safe and highly effective.

Neurocristopathy is characterized as having a common origin in aberrant neural crest development. Congenital central hypoventilation syndrome (Ondine's curse) is characterized by marked depression of respiratory drive during sleep and normal ventilation while awake because of no response to both hypercapnea and hypoxia. The girl was full-term, weighing 3020 grams. The girl had poor respiratory effort at birth, but improved with oxygen supply and stimulation. abdominal distention and calcification were noted. During laparotomy transitional zone was found at distal jejunum; a jejunostomy was constructed. Numerous attempts at extubation failed because of apnea. The results of an apnea work-up, including brain sonography, echocardiogram, were normal. The girl died of sepsis at 37 days of age. para-aortic ganglioneuroblastoma was found on autopsy. We experienced a newborn with congenital central hypoventilation syndrome, Hirschsprung's disease and congenital ganglioneuroblastoma representative of neurocristopathy.

Undifferentiated (embryonal) sarcoma is a rare malignancy of the liver in children and young adults. Seven cases of undifferentiated (embryonal) sarcoma of the liver pathologically verified at Seoul National University Children's Hospital between 1986 and 1999 were retrospectively analyzed. There were three girls and four boys, and their mean age at diagnosis was 12.1 years (range 7–13 years). Six patients presented with an abdominal mass or pain, and one with weight loss. Tumor size ranged from 8.0 × 8.0 cm to 15.0 × 15.0 cm. Four tumors were located in the right lobe, two in the left lobe and one in both. One patient died during chemotherapy. Initial complete resection was accomplished in three patients. Two patients underwent complete resection after chemotherapy. Five patients with complete resection survived without evidence of disease for 8, 11, 13, 28, and 84 months. A patient with partial resection and chemotherapy died of sepsis during chemotherapy 19 months after complete surgical resection. Adjuvant chemotherapy and radiotherapy were performed in all patients after complete surgical resection. In conclusion, though undifferntiated (embryonal) sarcoma of the liver is highly malignant, the combination therapy of surgery, chemotherapy and radiotherapy appears to result in a favorable prognosis