Spectrum of MNX1 Pathogenic Variants and Associated Clinical Features in Korean Patients with Currarino Syndrome

BACKGROUND: The major genetic cause of Currarino syndrome (CS), a congenital malformation syndrome typically characterized by sacral agenesis, anorectal malformation, and presence of a pre-sacral mass, is known to be pathogenic variants in motor neuron and pancreas homeobox 1 (MNX1), which exist in almost all familial cases and 30% of sporadic cases. Less commonly, a large deletion or a complex rearrangement involving the 7q36 region is associated with CS. We investigated the spectrum of MNX1 pathogenic variants and associated clinical features in the Korean patients with CS. METHODS: We enrolled 25 patients with CS, including 24 sporadic cases and one familial case. Direct sequencing of MNX1 and multiplex ligation-dependent probe amplification were performed. We also analyzed clinical phenotypes and evaluated genotype-phenotype correlations. RESULTS: We identified six novel variants amongst a total of six null variants, one missense variant, and one large deletion. The null variants included four frameshift variants (p.Gly98Alafs*124, p.Gly145Alafs*77, p.Gly151Leufs*67, and p.Ala216Profs*5) and two nonsense variants (p.Tyr186* and p.Gln212*). The missense variant, p.Lys295Gln, was located in the highly-conserved homeobox domain and was predicted to be deleterious. A large deletion involving the 7q36 region was detected in one patient. Pathogenic variants in MNX1 were detected in 28% of all CS cases and 25% of sporadic cases. The clinical phenotype was variable in patients with and without pathogenic variants; no significant genotype-phenotype correlation was observed. CONCLUSIONS: This study revealed the spectrum and phenotypic variability of MNX1 pathogenic variants in the Korean population.

Clinical Study of Congenital Esophageal Stenosis: Comparison according to Association of Esophageal Atresia and Tracheoesophageal Fistula / 대한소아소화기영양학회지

PURPOSE: Congenital esophageal atresia (CES) is a rare congenital disease. The severity of symptoms is variable; thus, diagnosis is difficult and tends to be delayed. CES is frequently accompanied by esophageal atresia (EA) with/without tracheoesophageal fistula (TEF). We investigated the characteristics of CES by reviewing our experience with CES patients and researched the differences between CES with EA-TEF and isolated CES. METHODS: A total of 31 patients underwent operations for CES were reviewed retrospectively. The patients were divided into two groups according to the association with EA-TEF, and compared the differences. RESULTS: Sixteen boys and 15 girls were included. The mean age at symptom onset was 8 months old, and the mean age at diagnosis was 21 months old. Nine patients with EA-TEF were included group A, whereas the other 22 patients were assigned to group B. There were no differences in sex, gestational age, associated anomalies and pathologic results between the groups. In group A, the age at diagnosis and age at surgery were younger than in group B despite the age at symptom occurrence being similar. Postoperative complications occurred only in group A. CONCLUSION: In this study, symptoms occurred during the weaning period, and vomiting was the most frequent symptom. CES patients with EA-TEF tended to be diagnosed and treated earlier despite the age at symptom occurrence being similar. CES patients with EA-TEF had more postoperative complications; therefore, greater attention should be paid during the postoperative period.

Comparison of outcomes according to the operation for type A esophageal atresia

PURPOSE: The purpose was to evaluate outcomes according to different operative strategies of type A esophageal atresia (EA). METHODS: All patients who underwent surgery for type A EA between 1980 and 2011 were included. Patients were divided into 2 groups: E-E group included patients who received esophageal end-to-end anastomosis, whereas E-G group included patients who received esophago-gastric tube anastomosis. RESULTS: Twenty-two patients were included. The median gestational age was 37.5 weeks. The median birth weight was 2.5 kg. Twenty-one patients underwent gastrostomy as initial procedures, and one patient underwent primary esophageal end-to-end anastomosis. The median gap between both esophageal ends was six vertebral distance (VD). Seven patients underwent primary anastomosis of the esophagus, and 14 patients underwent gastric replacement. Three patients (13.6%) had anastomotic leakage and 10 patients (45.5%) had anastomotic stenosis. Most of the patients (90.9%) had gastroesophageal reflux, but only two patients required antireflux surgery. The median VD was significantly shorter in E-E group than in E-G group (3 VD vs. 6 VD). Stenosis was significantly more often in E-E group, but there was no significant difference in leakage and reflux symptoms. CONCLUSION: The treatment for type A EA can include E-E anastomosis or E-G anastomosis, depending on the length of the end-to-end interval after performing gastrostomy. Appropriate tension and blood flow in the anastomosis site are essential for preventing postoperative stenosis and leakage, and esophageal replacement with gastric tube is believed to be feasible and safe in cases where excessive tension is present.

Clinical Feature of Neonatal Neuroblastoma: Comparison of Outcome between Diagnosed Prenatally and at Postpartum Group / 소아외과

PURPOSE: Neonatal neuroblastoma (NBL) is the most common malignant tumor in neonates, but there have been few studies about it. The purpose of this study was to investigate the clinical features of NBL and to compare prenatal and postnatal diagnosed groups. METHODS: Nineteen patients who were diagnosed with NBL prenatally or within 28 days after birth from February 1986 to February 2013 in Seoul National University Hospital were enrolled in the study. The patients were categorized according to the International Neuroblastoma Staging System (INSS) and Children's Oncology Group (COG). Retrospective medical-record reviews were performed on these patients. The operative date, complication, pathological stage, and overall survival of the prenatally diagnosed group and the postpartum diagnosed group were compared. RESULTS: Tumor was detected via prenatal ultrasonography in 8 patients (42.1%), and 11 patients (57.9%) were diagnosed within 28 days after birth. Based on INSS, the patients were divided into the stage I (n=8), stage II (n=1), stage III (n=3), stage IV (n=4), and stage IVs (n=3) groups, respectively. Based on COG, on the other hand, the patients were divided into the low-risk (n=8), intermediate-risk (n=8), and high-risk (n=3) groups. The postoperative complication rate was 29%. One patient died from complications from chemotherapy. The other 18 patients' mean follow-up period was 77.7 months. The differences between the postoperative complication rate, proportion of early-stage tumor, and overall survival of the prenatal and postnatal groups were not statistically significant (p=0.446, p=0.607, p=0.414). CONCLUSION: NBL showed favorable outcomes but relatively higher postoperative complications. There seem to be no significant statistical differences in the postoperative complications, proportion of early-stage tumor, and overall survival between the prenatally diagnosed group and the postpartum diagnosed group.

Long Term Outcomes of Pediatric Liver Transplantation According to Age

Liver transplantation (LT) has been the key therapy for end stage liver diseases. However, LT in infancy is still understudied. From 1992 to 2010, 152 children had undergone LT in Seoul National University Hospital. Operations were performed on 43 patients aged less than 12 months (Group A) and 109 patients aged over 12 months (Group B). The mean age of the recipients was 7 months in Group A and 74 months in Group B. The patients' survival rates and post-LT complications were analyzed. The mean Pediatric End-stage Liver Disease score was higher in Group A (21.8) than in Group B (13.4) (P = 0.049). Fulminant hepatitis was less common in Group A (4.8%) than in Group B (13.8%) (P = 0.021). The post-transplant lymphoproliferative disorder and portal vein complication were more common in Group A (14.0%, 18.6%) than in Group B (1.8%, 3.7%) (P = 0.005). However, the 1, 5, and 10 yr patient survival rates were 93%, 93%, and 93%, in Group A and 92%, 90%, and 88% in Group B (P = 0.212). The survival outcome of pediatric LT is excellent and similar regardless of age. LTs in infancy are not riskier than those of children.

Characteristics of the Germline MEN1 Mutations in Korea: A Literature Review / 대한내분비외과학회지

PURPOSE: Multiple endocrine neoplasia type 1 (MEN-1) is an autosomal dominant disease caused by the MEN1 germline mutation. We reviewed previous reports in order to summarize the characteristics of germline MEN1 mutation in Korea. METHODS: We retrieved the relevant literature regarding MEN1 germline mutation in Korea using the Pubmed (http://www.pubmed.org/) and Koreamed (http://www.koreamed.org/) databases from 2000 to 2012. We evaluated the pedigree of the patients in order to exclude the same, repeated families. We collected all data on the types of mutations and clinical characteristics. RESULTS: There were nine studies with 12 cases of MEN1 mutations in Korea. Two cases were sporadic MEN-1. C.196_200dupAGCCC was reported in three families. There were six cases of frameshift mutation, three cases of missense mutation, two cases of nonsense mutation, and one case of splice site mutation. Five mutations were novel mutations not previously reported. CONCLUSION: We summarized the characteristics of germline MEN1 mutations in Korea. Genetic testing of MEN1 is rare in Korea; however, it will be useful in preclinical diagnosis and genetic counseling.

Development and Validation of Web-Based Nomograms to Predict Postoperative Invasive Component in Ductal Carcinoma in Situ at Needle Breast Biopsy / 대한의료정보학회지

OBJECTIVES: Although sonography-guided core needle biopsy is a highly targeted method, there is a possibility of an invasive component after surgical excision of ductal carcinoma in situ (DCIS) of the breast. This study was performed to develop and validate nomograms to predict the postoperative invasive component in DCIS at core needle biopsy. METHODS: Two nomograms were developed using the data of previous meta-analysis and multivariate analysis. Nomograms were validated externally using the data of the authors' affiliation. The accuracy was validated by the expected-to-observed ratio and the Hosmer-Lemeshow goodness-of-fit test. Discrimination was validated by the area under the curve (AUC) of receiver operating characteristic (ROC) curve analysis. RESULTS: The nomogram using the meta-analysis study data was developed at http://dcis-m.surgery.kr.pe/, and the nomogram using the multivariate analysis study data was developed at http://dcis-k.surgery.kr.pe/. The Hosmer-Lemeshow goodness-of-fit test showed that the nomogram using multivariate analysis data (p = 0.131) was better calibrated than that using meta-analysis data (p < 0.001). ROC curve analysis showed statistically significant power of discrimination in both nomograms (AUC = 0.776, 0.751). CONCLUSIONS: Both nomograms showed statistically significant discriminatory power, but the nomogram using the data of multivariate analysis was simpler and more reliable. These would be useful for the prediction of invasive cancer and the need for sentinel node biopsy in DCIS at core needle biopsy.

Risk Factors for Malignancy of Pheochromocytoma and Abdominal Paraganglioma in Children: Clinicopathologic Perspectives

No abstract available.

Experience with Enterostomy Closure in Very Low Birth Weight Infants

The survival of Very Low Birth Weight (VLBW) infants has been improved with the advancement of neonatal intensive care. However, the incidence of accompanying gastrointestinal complications such as necrotizing enterocolitis has also been increasing. In intestinal perforation of the newborn, enterostomy with or without intestinal resection is a common practice, but there is no clear indication when to close the enterostomy. To determine the proper timing of enterostomy closure, the medical records of 12 VLBW infants who underwent enterostomy due to intestinal perforation between Jan. 2004 and Jul. 2007 were reviewed retrospectively. Enterostomy was closed when patients were weaned from ventilator, incubator-out and gaining adequate body weight. Pre-operative distal loop contrast radiographs were obtained to confirm the distal passage and complete removal of the contrast media within 24-hours. Until patients reached oral intake, all patients received central-alimentation. The mean gestational age of patients was 26(+2) wks (24(+1)~33(+0) wks) and the mean birth weight was 827 g (490~1450 g). The mean age and the mean body weight at the time of enterostomy formation were 15days (6~38 days) and 888 g (590~1870 g). The mean body weight gain was 18 g/day (14~25 g/day) with enterostomy. Enterostomy closure was performed on the average of 90days (30~123 days) after enterostomy formation. The mean age and the mean body weight were 105 days (43~136 days) and 2487 g (2290~2970 g) at the time of enterostomy closure. The mean body weight gain was 22 g/day after enterostomy closure. Major complications were not observed. In conclusion, the growth in VLBW infants having enterostomy was possible while supporting nutrition with central-alimentation and the enterostomy can be closed safely when the patient's body weights is more than 2.3 kg.

Neuroblastoma: Review of 20-year Experiences

Neuroblastoma is the most common extracranial solid tumor in children. We retrospectively analyzed the results of neuroblastoma treatment of 191 patients (116 males and 75 females) treated between January 1986 and December 2005 at the Department of Pediatric Surgery and the Department of Pediatrics, Seoul National University Children's Hospital. The mean age at diagnosis was 3.1 years (0.1 yrs - 13.5 yrs). Forty-seven patients were under 1 year of age. The mean follow-up period was 57.3 months (24 days - 19.1 yrs). Patients were classified into two groups according to the completeness of resection of the primary tumor; (1) gross total resection (GTR) and (2) incomplete resection (IR). The number of patients in stages I, II, III, IV, IV-S were 17 (8.9 %), 12 (6.3 %), 43 (22.5 %), 114 (59.7 %), 4 (2.1 %), respectively. GTR was achieved in 120 patients and IR in 71 (22 stage III, 47 stage IV, 1 stage IV-S, 1 brain). Overall survival (OS) was 65.2 % and event-free survival (EFS) was 48.6 %. EFS were 100 %, 75 %, 66.8 %, 31.3 %, 75 % at stage I, II, III, IV, IV-S, respectively. There was no significant difference in EFS according to the completeness of resection. EFS was improved in GTR group (p=ns) of stage III, but by contrast, stage IV patients showed worse EFS in GTR group. EFS was improved significantly after the introduction of autologous stem cell transplantation (ASCT) (58.1% vs. 40.6%, p=.029). The EFS improved significantly after the introduction of ASCT in IR group (p=.009) rather than GTR group (p=ns). The EFS of the patients under 1 year of age (N=47) was better than the patients over 1 year of age (N=144) significantly (75.5 % vs. 39.4 %, p=.0034). The prognosis of neuroblastoma was related to the INSS stage and age at diagnosis. The survival of IR group significantly improved after ASCT.

Abdominal Inflammatory Myofibroblastic Tumor in Children

Inflammatory myofibroblastic tumor (IMT) is a rare reactive lesion characterized by the feature of myofibroblasts and a mixed inflammatory infiltrate that rarely undergoes malignant transformation. Extrapulmonary IMTs in children have been described involving the mesentery, omentum, retroperitoneum, abdominal soft tissues, liver, bladder, mediastinum, head and neck, extremity, appendix, and kidney. Medical records of children treated with abdominal IMT between 1985 and 2005 were reviewed retrospectively. Seven children were treated for IMT with the mean age of 3y 2m (range, 1y 1m to 14y). Tumors were located in transverse mesocolon (n=2), omentum (n=1), porta hepatis (n=2), complex site (antrum, duodenum, common bile duct, porta hepatis) (n=2). The symptoms included abdominal mass, fever, jaundice, abdominal pain and anemia. The masses were excised totally in transverse mesocolon, omentum IMT and there is no evidence of recurrence (follow-up periods: 6y 8m, 8y 9m, 4y 10m). In porta hepatis IMT, liver transplantations were performed and there is no evidence of recurrence (follow period: 6y 8m, 8y 7m). In one case of complex site IMT, partial excision of mass was performed and he still survived with no change of the residual tumor during follow-up period. The other one of complex site IMT denied further treatment after the biopsy. In conclusion, complete surgical excision including liver transplantation and close follow-up are mandatory for the abdominal IMT in child.

The Usefulness of Cephalic Vein Cut-Down for Totally Implantable Central Venous Port in Children

The usefulness of totally implantable central venous port for long-term intravenous infusion is widely accepted in children. Usually the catheters are placed through the internal or external jugular vein. In case of jugular vein cut-down, two separate incisions are needed for catheter and port respectively. Patients also feel uncomfortable as the catheter run through the neck. However these disadvantages can be overcome by using the cephalic vein (CV). We reviewed our experiences on CV cut-down for totally implantable central venous port in children. From January 2002 to December 2006, 201 patients (M:F=127:74) underwent 218 central venous port insertions. Mean age at operation was 5.9 years (2 months - 19 years). Indications included chemotherapy (N=167), long-term intravenous antibiotics infusion (N=36), and total parenteral nutrition (N=15). CV was selected preferentially. The incision includes the deltopectoral triangle laterally, and both the CV cut-down and port insertion were achieved with a single incision. The number of insertion through external, internal jugular vein, and CV was 77, 66 and 75, respectively. The median age, height and body weight were higher in CV cut-down group. The youngest age for CV cut-down was 8 months, the shortest height was 69 cm and the smallest body weight was 5.9 kg. Of 118 trials of CV cut-down, cut-down was successful in 75 cases (63.6 %). CV was absent in 10 cases(8.4 %) and CV was sacrificed after catheter tip malposition in 10 cases (8.4 %). There was only one complication, in which the catheter was inserted into the minute branch of subclavian artery. The CV cut-down method for totally implantable central venous port was safe and feasible in selected groups of patients in children. In addition, preservation of jugular vein and a more favorable cosmetic effect are other benefits of CV cut-down.

Results of Treatment of Rhabdomyosarcoma in Children

The survival rate for rhabdomyosarcoma (RMS) has significantly improved after the introduction of combined multimodality treatment. We report the 20-year treatment outcome of pediatric rhabdomyosarcoma in a single institution. The medical records of 16 patients treated for rhabdomyosarcoma between December 1986 and August 2007 at the Department of Pediatric Surgery, Seoul National University Children's Hospital, were retrospectively reviewed. Mean age at diagnosis was 7.1 years (range: 1.3 -14.2 years). Retroperitoneum was the most common primary site (n=7, 43.8%), and embryonal type was predominant (n=11, 6%). Before the treatment, most patients were in advanced TNM stage (stage III 50%, IV; 25%). The patient distribution according to the Intergroup Rhabdomyosarcoma Study Clinical Grouping System (IRS-CGS) was as follows; Group I 31.3%, Group II 12.5%, Group III 31.3% and Group IV 25%. Patients were classified into three groups according to the extent of resection of the primary tumor; complete resection (CR, n=5; 31.3%), gross total resection (GTR, n=7; 43.8%) and incomplete resection (IR, n=4; 25%). Recurrence was observed in 9 patients (56.3%) while there was no recurrence in CR patients. All patients with recurrence were identified as moderate or high-risk according to the IRS-V Risk Group. Pre-treatment TNM stage of RMS in our institution was advanced with aggressive clinical feature, however post- surgical conditions according to IRS-CGS were similar to the previous reports by IRS. This suggests that down-staging of IRS-CGS was achieved with multimodality treatment with CR or GTR. It also suggests that complete resection is the most important prognostic factor in the treatment of RMS in children. Patients classified as moderate or high-risk need close follow-up due to high recurrence rate. In case of localized recurrence, better outcome may be achieved with multimodality treatment including limited surgery.

Congenital Sialoblastoma: a Case Report

Sialoblastoma is a rare tumor of salivary gland origin, developing in the fetal or neonatal period. Most tumors arise in parotid gland, and rarely in submandibular gland. Because of its rare incidence, diagnosis of the sialoblastoma in head and neck tumors of children is not easy. The case of a congenital submandibular gland sialoblastoma is presented. A neonate was transferred right after birth due to a submandibular mass. CT scan showed a lobulating mass located posterior to the left submandibular gland, suggesting neurogenic tumor or myofibroma. The tumor was excised easily after division of a duct-like structure connecting with the submandibular gland. The microscopic findings showed the basaloid cells and ductules forming cellular nests, separated by thin fibrous tissue. Immunohistochemical staining was positive for cytokeratin, vimentin and Ki-67, which was consistent with sialoblastoma.

An Incidentally Detected Ventriculoperitoneal Shunt Catheter in the Scrotum

Migration of a peritoneal catheter of a ventriculoperitoneal shunt into the scrotum is a rare complication. We treated a case of catheter migration in the scrotum. A 12-year old boy, who had had a ventriculoperitoneal shunt at the age of 4 months due to neonatal hydrocephalus, visited the outpatient clinic because of a right inguinal hernia. On physical examination, a firm mass was found in the left scrotum. Pelvic X-ray demonstrated a coiled catheter in the left scrotum. The catheter was successfully removed by exploring the left patent processus vaginalis after high ligation of the hernia sac. This case suggests a suction action of the patent processus vaginalis and the possibility of catheter migration long after shunt catheter insertion.

Result of Secondary Surgery after Primary Surgery for Esophageal Atresia Anomalies

We reviewed the records of 25 patients who were re-operated upon after primary repair of esophageal atresia with or without fistula at the Department of Pediatric Surgery, Seoul National University Children's Hospital, from January 1997 to March 2007. Types of the esophageal atresia anomalies were Gross type A in 5 patients, C in 18, and E in 2. The indications for re-operation were anastomosis stricture (n = 14), tracheo-bronchial remnant (n = 4), persistent anastomosis leakage (n = 3), recurrent tracheo-esophageal fistula (n = 2) and esophageal web (n = 2). The interval between primary and secondary surgery was from 48 days to 26 years 5 months (mean: 2 years and 4 months). Four patients required a third operation. The interval between the second and third operation was between 1 year 1 month and 3 year 10 month (mean: 2 years 5 months). Mean follow up period after last operation was 35 months (1 years-8 years 6 months). The secondary surgery was end-to-end esophageal anastomosis in 15, esophagoplasty in 5, gastric tube replacement in 5. After secondary operation, 6 patients had anastomosis stricture (4 patients were relieved of the symptoms by balloon dilatation, 2 patients underwent tertiary operation). Five patients had leakage (sealed on conservative management in all). Two patients had recurrent tracheo-esophagel fistula (1 patient received chemical cauterization and 1 patient underwent tertiary operation). Currently, only one patient has feeding problems. There were no mortalities. Secondary esophageal surgery after primary surgery for esophageal atresia was effective and safe, should be positively considered when complications do not respond to nonoperative therapy.

Clinical Review of the Pediatric Primary Adrenocortical Tumors

Adrenocortical tumors are very rare in children and the clinical course is not clearly understood. The aim of this study is to review the clinical characteristics and courses of pediatric adrenocortical tumors. The medical records of patients who underwent surgery for primary adrenal tumor at the Department of Surgery, Seoul National University hospital, from Jan. 1986 to Feb. 2006 were reviewed. There were 10 adrenocortical tumor patients; 5 had adrenocortical adenoma and 5 adrenocortical carcinoma. All of the adrenocortical adenomas presented as functioning tumors, i.e., Cushing syndrome or virilization. However, only 2 patients had functioning adrenocortical carcinoma. Median size of adenoma was 5 (3.3-6) cm, and carcinoma 12.5 (6.5-13)cm. Adenomas were smaller than 6 cm and carcinomas were larger than 6.5cm. Surgical resection alone cured all adrenocortical adenoma patients, and they were all alive without recurrence. Three of 5 adrenocortical carcinoma patients died of tumor recurrence despite radical surgery and chemotherapy. There were 2 long-term survivals for adrenocortical carcinoma, one patient survived 10 years without recurrence until he died of newly developed osteosarcoma, and the other patient is alive without recurrence for 20 years. As the prognosis of pediatric adrenocortical carcinoma is poor, peri-operative aggressive chemotherapy is suggested in addition to radical surgery.

Analysis of the Outcome of Tunneled Hemodialysis Catheters in Children according to the Indications for Use

PURPOSE: The tunneled hemodialysis catheter has been widely used for a temporary or an alternative permanent vascular access in patients requiring hemodialysis. The tunneled hemodialysis catheter is also widely used for a reliable vascular access in children who need stem cell transplantation. METHOD: We reviewed the results of 150 catheters inserted in 108 patients for the duration of the indwelling catheter, the complication rate and the reasons for insertion and removal. RESULT: The mean duration of the indwelling catheter was 5.7 months (1 d~52.2 mo). In the stem cell transplantation group, the mean duration of the indwelling catheter was significantly longer than for the hemodialysis group (mean: 9.9 mo vs. 3.6 mo, P<0.05). Fifty-one catheters (39.8%) were removed due to complications. The most common complications were infection (n=23: 17.9%) and dislocation (n=15: 11.7%). In the hemodialysis group, the complication-related catheter removal was more frequent than in the stem cell transplantation group (43.9% vs. 32.6%, P<0.05). CONCLUSION: The tunneled hemodialysis catheter remains a reliable short-term vascular access for hemodialysis and a good vascular access in stem cell transplantation.

Natural Course and Treatment of Fetal Ovarian Cysts

With the development of fetal ultrasonography, detection of fetal ovarian cysts has been increased. Although ovarian cyst formation during the perinatal period is a self limiting process, there is still considerable controversy regarding the best treatment of the fetal ovarian cyst. The purpose of this study is to evaluate the natural history of fetal ovarian cysts and to analyze the result of treatment. From 1995 to 2004, 31 consecutive fetuses with ovarian cysts were followed by ultrasonography during the perinatal period. The fetal ovarian cyst was diagnosed by prenatal ultrasonography between 25weeks and 38 weeks and the mean size of the cysts was 5cm (ranged from 2 to 8cm). At birth, 3 cysts disappeared. In 2 cases, the diagnoses were changed to multicystic kidney disease and intestinal duplication. During following up of 26 cysts, 15 cysts have resolved completely. Seven cysts required oophorectomy because of cyst torsion (n=3), differentiation of tumorous condition (n=2), increased size of cyst (n=1), and large size (8cm) of cyst at birth (n=1). Fetal ovarian cyst should primarily be observed, and only in the limited cases, surgical treatment would be required for the risk of complications such as torsion and differentiation from benign to malignant pathology.

The Expression of nNOS in Hirschsprung's Disease

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.