[Focal spontaneous colic perforation in term or near-term neonates: rare and potentially insidious]. / Perforation colique néonatale focale spontanée en dehors de la grande prématurité : rare et potentiellement insidieuse.

Two cases of neonatal focal spontaneous colic perforations are reported. The 1st infant, born at 36 3/7 weeks gestational age, presented on day 3 with crying, abdominal distension, and liquid stools. Clinical examination showed a slightly irritable hypothermic (35.7 °C) infant with a distended abdomen and few bowel sounds. Blood tests were normal apart from an elevated C-reactive protein level (59 mg/l). The abdomen x-ray was erroneously considered normal. The infant's condition remained stable for nearly 3 days. After reviewing the initial x-ray, pneumoperitoneum was suspected and confirmed by a cross-table lateral abdominal x-ray. The infant was started on antibiotics and operated. Macroscopically, the entire gut was normal apart from a focal sigmoid perforation, which was stitched. A transmural colic biopsy revealed focal vascular dilation but was negative for necrotising enterocolitis or Hirschsprung disease. The infant recovered quickly. She is now a healthy, normal 3-year-old. The 2nd infant, born at 38 5/7 weeks gestational age, presented between day 1 and 2 with clinical signs of infection associated with slowly progressive ileus. The chest and abdomen x-ray was mistakenly considered normal. Frank septicemia developed. After reviewing the initial x-ray, pneumoperitoneum was suspected and confirmed by a cross-table lateral abdominal x-ray. The infant was operated. Macroscopically, the small intestine was normal, the ascending and transverse colons were dilated, and the descending and sigmoid colons were narrow. Three cecal perforations were discovered and stitched. An ileostomy and multiple colic biopsies were also performed. The postoperative course was complicated by persistent septic ileus due to descending and sigmoid colon leaks, which led to colic resections with end-to-end anastomosis. Rectal aspiration biopsies were also performed. At 1 month of age, the infant was discharged from the hospital. The ileostomy was closed in two steps at 2 and 5 months of age. A normal sweat test excluded cystic fibrosis. All colic and rectal biopsies revealed nonspecific inflammatory signs and excluded necrotizing enterocolitis and Hirschsprung disease. Nonspecific irregular thinning of muscularis mucosae and muscularis propria were observed in the two resected colic segments. The boy is now a healthy 7-year-old. The incidence of neonatal focal spontaneous colic perforations at term or close to term is unknown but probably very rare. Our department is the neonatal referral center for approximately 14,000 annual births. In the last 10 years (2000-2009), out of 5115 neonatal admissions in our unit, only ten cases have presented a neonatal spontaneous intestinal perforation, seven of ten in very-low-birth-weight infants and three of ten in term or near-term neonates (one with Hirschsprung disease and the two cases reported herein). In the same period, 108 infants suffered from necrotizing enterocolitis, seven of 108 were term infants and 6 out of 7 had a congenital heart disease. The medical literature is poor on the subject of focal spontaneous colic perforations at term; no risk factor is described. The most specific clinical sign seems to be the abdominal distension. The presence of pneumoperitoneum on an abdominal x-ray is the most sensitive paraclinical sign. In case of an intestinal perforation, surgery must be performed quickly. The vital prognosis seems to be good. The objective of this study was to draw pediatricians' attention to focal spontaneous colic perforations in term or close to term newborns. In the cases reported, the diagnostic delays could have been prevented if the entity - with its radiological manifestation - had been well known.

Combination of immunohistochemistry and ploidy analysis to assist histopathological diagnosis of molar diseases.

BACKGROUND: Differential diagnosis between hydropic abortion, partial mole and complete mole is still a challenge for pathologists but really important for patient management. MATERIAL AND METHOD: In this study, we have evaluated 111 products of conception from the first trimester. Histological analysis was made according to the main diagnostic histopathological features described in the literature and the cases were categorized in hydropic abortus (HA), partial mole (PM) and complete mole (CM). Immunohistochemistry was performed using monoclonal antibody against p57(kip) protein a putative paternally imprinted inhibitor gene and DNA ploidy was analysed in all cases by image cytometry. RESULTS: All 23 HAs presented a diploid DNA content and were p57(kip2) positive. From the 28 CMs, 12 cases (43%) were diploid and 16 cases (57%) were tetraploid but no expression of p57(kip2) was found with positive internal controls. From the 60 PMs, 58 cases were positive for p57(kip2) expression and 53 cases (88%) were triploid, 6 cases (10%) tetraploid and 1 case (2%) diploid. CONCLUSION: This study on 111 cases of early pregnancies confirms the usefulness of immunohistochemistry and cytometry but demonstrates the importance of the combination of both techniques to assist histology for the best reliable diagnosis.

Digital image DNA cytometry: a useful tool for the evaluation of malignancy in biliary strictures.

BACKGROUND: Cytologic evaluation of the biliary tract strictures is nowadays widely used for distinguishing between benign and malignant lesions but remains a challenge for some problematic cases. Digital Image cytometry (DNA-cytometry) helps cytopathologists to resolve some unclear situations. METHODS: We have analysed 41 specimens of bile duct brushings obtained from patients during ERCP (11 benign cases, 7 suspicious for malignancy cases and 23 malignant cases) by DNA-cytometry and correlated them with the histological biopsy counterpart. RESULTS: All eleven cytological and histological benign cases were DNA-diploid and among 22 patients with malignant cytological and histological diagnosis 21 were DNA-aneuploid. One case considered malignant by the cytopathologist revealed DNA-aneuploid but malignancy could not be confirmed by histology. The analysis of the suspicious for malignancy cases revealed that all DNA-aneuploid cases were malignant and all DNA-diploid cases were benign referring to the follow-up of the patients. The comparison between cytology alone and cytology combined with DNA-cytometry related to the histological diagnosis (gold standard) resulted in a sensitivity of 100% and a specificity of 79% for cytology alone; a specificity of 94% and a sensitivity 92% for DNA-cytometry and a specificity of 93% and a sensitivity of 100% with combined analyses. The positive predictive value was 90% for cytology, 96% for DNA-cytometry and for both analyses. The negative predictive value showed 100% for cytology, 89% for DNA-cytometry and 100% for combined studies. CONCLUSIONS: Despite the limited number of patients involved in the study, the results obtained indicate an increased of specificity and of positive predictive value using DNA-cytometry. These results confirm the pertinence of these method for challenging cases, in conjunction with other available diagnostic tools.

p53 gene mutation and protein accumulation during neoplastic progression in Barrett's esophagus.

The aim of the present study was to characterize expression and mutation of p53 during the neoplastic progression from Barrett's esophagus to adenocarcinoma and to test the reliability of immunohistochemistry for p53 overexpression as an indicator of p53 mutation in this context. The association of both gene mutation and protein accumulation with clinicopathological findings and survival was also studied. A total of 77 samples from 30 esophagectomy specimens with Barrett's esophagus and adenocarcinoma of patients in longitudinal clinical follow-up were analyzed. Different lesions (intestinal metaplasia, dysplasia, and adenocarcinoma) as well as normal squamous-cell esophageal epithelia were sampled from formalin-fixed, paraffin-embedded tissues by microdissection. Mutations in p53 Exons 5 to 9 were detected by polymerase chain reaction-single-strand conformation polymorphisms (PCR-SSCP) and confirmed by direct DNA sequencing. Nuclear accumulation of p53 protein was analyzed immunohistochemically from tissue sections adjacent to those used for microdissection. p53 gene mutations were found in 17 and p53 protein accumulation were found in 20 tumor samples. Of the 17 adenocarcinomas with a p53 mutation, 16 stained positive for p53 protein. p53 mutations were detected significantly more frequently in high-grade dysplastic than in low-grade dysplastic lesions (77% versus 29%, P < 0.01). In contrast, nuclear accumulation of p53 was detected in 85% of high-grade and 71% of low-grade dysplastic lesions. In eight cases with p53 mutation, the mutation identified in the tumors was also detected in premalignant lesions, mainly in high-grade dysplasia. In four cases of p53-mutated tumors, clones with different p53 mutations were detected in premalignant lesions. Neither p53 mutations nor p53 protein accumulations were found in metaplastic lesions. In summary, we found that p53 mutations occurred mainly during the transition from low-grade to high-grade dysplasia in the neoplastic progression of Barrett's esophagus but not in the nondysplastic Barrett's mucosa. Mutational analysis of p53 by PCR-SSCP and p53 accumulation by immunohistochemistry were mostly concordant in adenocarcinoma and high-grade dysplastic lesions but frequently discordant in low-grade dysplastic lesions. No correlation between p53 gene mutation or p53 accumulation and clinicopathological findings was observed in this study.

Promoter methylation analysis on microdissected paraffin-embedded tissues using bisulfite treatment and PCR-SSCP.

Methylation-sensitive single-strand conformation analysis (MS-SSCA) is a new method of screening for DNA methylation changes. The combination of bisulfite modification and PCR results in the conversion of unmethylated cytosines to thymines, whereas methylated cytosines remain unchanged. This sequence conversion can lead to methylation-dependent alterations of single-strand conformation, which can be detected by SSCA. An analysis of mixtures of methylated and unmethylated DNA at known ratios revealed that the relative intensities of the corresponding bands following MS-SSCA were maintained. MS-SSCA was applied for methylation analysis of human p16 promoter region using genomic DNA obtained from either frozen, fixed, or microdissected fixed tissue sections. MS-SSCA is a rapid, specific, and semiquantitative approach that allows the detection of methylation of the p16 gene promoter. In reconstruction experiments, the method permits the detection of 10% or less of cells harboring a methylated p16 promoter. We have been successful in analyzing by MS-SSCA almost all (96%) tumor samples microdissected from archival paraffin-embedded fixed tissue sections and obtaining reproducible results. In addition, when microdissection was performed, the clonality of this genetic alteration could be identified.

Primary neuroendocrine carcinoma of the liver: an autopsy case.

An autopsy case of primary hepatic neuroendocrine carcinoma is described. A 72-year-old man had a large tumor mass measuring 22 cm in its greatest diameter and localized to the right, left and caudal lobes of the non-cirrhotic liver. Microscopically, the tumor was composed of middle-sized pleomorphic cells organized in ribbons or trabeculae, with scanty intersecting fibrous septae. Immunohistochemically, the tumor cells were positive for multikeratin C11, chromogranin A and synaptophysin. The patient also had metastases in the bone marrow. No alternative primary source of endocrine tumor was detected. The patient died 4 days after presentation.

Nuclear accumulation of beta-catenin is a common and early event during neoplastic progression of Barrett esophagus.

Our aim was to characterize expression and mutation of beta-catenin in the progression of Barrett esophagus to adenocarcinoma. Immunohistochemical analysis of beta-catenin was performed on paraffin-embedded tissue from 30 cases with adenocarcinomas and premalignant lesions. To determine whether there is a correlation between beta-catenin nuclear accumulation and exon 3 mutation of this gene, mutational analysis by polymerase chain reaction-single-strand conformation polymorphism was performed on DNA extracted from the same 30 adenocarcinomas. As a result, the prevalence of reduced expression of beta-catenin on the membrane, with or without nuclear staining, increased significantly from low-grade (LG) to high-grade (HG) dysplasia. Focal nuclear staining for beta-catenin was present in 19 cases of adenocarcinoma, and nuclear staining was associated significantly with progression from metaplasia to LG dysplasia. In addition, in glands with clear histologic transition from metaplasia to LG dysplasia, nuclear accumulation of beta-catenin was found only in the LG dysplastic areas. No mutation in exon 3 of the beta-catenin gene was detected in adenocarcinomas. These results demonstrate that disturbance of the APC/beta-catenin pathway, as indicated by nuclear accumulation of beta-catenin, is a common and early event during neoplastic progression in Barrett esophagus.

Evaluation of heterogeneity of DNA ploidy in early gastric cancers.

DNA ploidy has been shown to be a predictive parameter for prognosis in various solid tumours. The prognostic value of DNA-ploidy in gastric cancers is still a matter of controversy. A possible explanation for the discrepant results reported in the literature could be sampling error in tumours with multiple stemlines differing in DNA-ploidy. In order to determine whether or not such heterogeneity exists in early gastric carcinoma, we have performed DNA cytophotometry on multiple samples of a group of 17 early gastric carcinomas, of which 8 were pure intramucosal and 9 were infiltrating into the submucosa. We found an aneuploid DNA-stemline in 8 (47%) early gastric cancers, more often in tumours invading into the submucosa (5/9) than in purely mucosal tumours (3/8). Multiple DNA-stemlines were found more frequently in submucosally infiltrating tumours (4/5). These results confirm the presence of DNA-aneuploid early gastric carcinoma which are frequently heterogeneous and suggest that heterogeneity occurs more frequently in tumours invading the submucosa. This heterogeneity is best detected by analysing multiple samples of tumours for DNA-ploidy.

Early gastric carcinoma with focal advanced cancer: a particular subtype of gastric carcinoma.

Early gastric cancer (EGC) is defined as a carcinoma limited to the mucosa or mucosa and submucosa, irrespective of whether metastasis to lymph nodes has occurred. EGC presents a much more favorable prognosis than advanced gastric carcinoma (AGC), with a 5-year survival rate between 88% and 96% for EGC versus 45% to 50% for AGC. Moreover, some gastric cancers appear as a more or less extended EGC with focal AGC (fAGC). The purpose of this study was to analyze prognostic factors in this intermediate group of tumors. From 1981 to 1992, among the 615 gastrectomy specimens with carcinoma examined at the Institute of Pathology of the University of Lausanne, only 19 tumors corresponded to the criteria of EGC with fAGC. Clinicopathologic features were studied, and a cytophotometric DNA analysis was performed. Our results show a 5-year survival rate for EGC with fAGC of 61% (11 of 18 patients alive), intermediate between that of EGC and AGC. No significant correlations were found between the most known predictive factors and prognosis. Most tumors analyzed (16 of 19) showed a diploid DNA content in the superficial as well as in the invasive areas. Contrary to the findings in the literature, which show a high-ploidy DNA pattern in most AGC, our cases show low-ploidy DNA even in the invasive portion of the tumors. In conclusion, we show that EGC with focal AGC represents a gastric cancer with an intermediate prognosis and, therefore, must be considered as a specific subtype of gastric carcinoma.

Localization of neuropeptide Y and its C-terminal flanking peptide in human renal tissue.

We produced and characterized three anti-C-flanking peptides of neuropeptide Y (CPON) monoclonal antibodies. The Ka for these antibodies ranged from 0.4 to 0.8 x 10(8) l/mol with an IC50 for CPON(1-30) at about 20 nM as determined by ELISA. All these antibodies are IgG1 and recognize the 16-30 part of CPON. These antibodies and a specific anti-NPY monoclonal antibody were used to study the localization of CPON and NPY in the human kidney. The avidin-biotin technique was employed. NPY and CPON immunoreactivities were present in large amount in the renal tubules of the human kidney but not in the glomeruli. No labeling was found within the renal arterioles and veins, but some immunoreactivity was evidenced in the perivascular area. Because no specific receptor for CPON has been described to date, the presence of this peptide in the tubules may be due to a tubular reabsorption or perhaps to a local synthesis of pro-NPY.