Gene expression profiling identifies different sub-types of retinoblastoma.

BACKGROUND: Mutation of the RB1 gene is necessary but not sufficient for the development of retinoblastoma. The nature of events occurring subsequent to RB1 mutation is unclear, as is the retinal cell-of-origin of this tumour. METHODS: Gene expression profiling of 21 retinoblastomas was carried out to identify genetic events that contribute to tumorigenesis and to obtain information about tumour histogenesis. RESULTS: Expression analysis showed a clear separation of retinoblastomas into two groups. Group 1 retinoblastomas express genes associated with a range of different retinal cell types, suggesting derivation from a retinal progenitor cell type. Recurrent chromosomal alterations typical of retinoblastoma, for example, chromosome 1q and 6p gain and 16q loss were also a feature of this group, and clinically they were characterised by an invasive pattern of tumour growth. In contrast, group 2 retinoblastomas were found to retain many characteristics of cone photoreceptor cells and appear to exploit the high metabolic capacity of this cell type in order to promote tumour proliferation. CONCLUSION: Retinoblastoma is a heterogeneous tumour with variable biology and clinical characteristics.

A congenital smooth muscle hamartoma masquerading as a reticulate vascular naevus.

Smooth muscle hamartoma (SMH) is a benign congenital or acquired hamartomatous lesion comprising a dermal proliferation of smooth muscle bundles. We report a case of congenital SMH with an unusual clinical appearance. A 3-year-old girl presented with an asymptomatic atrophic linear lesion on the posterior surface of her right thigh, which had been present since birth. The striking resemblance to a vascular lesion initially led to the erroneous clinical diagnosis of atrophic reticulate vascular naevus. However, a skin biopsy showed typical features of SMH. To our knowledge, SMH with linear configuration has only been described in two previous cases, and there are no previous reports of SMH with such a marked resemblance to a vascular lesion.

Chronic hepatitis C in children--review of natural history at a National Centre.

The natural history of hepatitis C virus (HCV) infection in adults has been established, but less is known about outcome in children. We conducted a retrospective review of patients referred to Birmingham Children's Hospital Liver Unit, from 1991 till 2008, with the diagnosis of HCV was undertaken. Only children with documented positive HCV RNA and a minimum duration of follow-up of 6 months were included. One hundred and thirty-three children were identified. The route of transmission was transfusion acquired in 47%, vertically acquired in 49% and transplantation in 2%. Since 2000, most children were infected vertically. The overall rate of spontaneous viral clearance was 17.5% with higher clearance (27%) in the transfusion group compared to the vertically acquired group (9%). Seventy-six had a liver biopsy at diagnosis. There was no evidence of fibrosis in 46%, mild fibrosis in 50% and moderate to severe fibrosis in 4%. None had cirrhosis. There was a statistically significant relationship between fibrosis score and older age at the time of biopsy (P = 0.02) and longer duration of infection (P = 0.05). Eighty children received treatment for HCV. Sustained viral response (SVR) was influenced by viral genotypes, with significantly increased response rates in genotypes (G) 2 and 3 compared to G 1 and 4. Vertical infection is now the major route of HCV infection in children in the UK. Histological changes were mild at diagnosis, but the severity of fibrosis progressed with age. Consideration should be given to improve detection and diagnosis to refer children to specialist centres for management and antiviral therapy before developing fibrosis.

Induction of protective cytotoxic T cell responses in the presence of high titers of virus-neutralizing antibodies: implications for passive and active immunization.

The effect of preexistent virus-neutralizing antibodies on the active induction of antiviral T cell responses was studied in two model infections in mice. Against the noncytopathic lymphocytic choriomeningitis virus (LCMV), pretreatment with neutralizing antibodies conferred immediate protection against systemic virus spread and controlled the virus below detectable levels. However, presence of protective antibody serum titers did not impair induction of antiviral cytotoxic T lymphocyte (CTL) responses after infection with 10(2) PFU of LCMV. These CTLs efficiently protected mice independent of antibodies against challenge with LCMV-glycoprotein recombinant vaccinia virus; they also protected against otherwise lethal lymphocytic choriomeningitis caused by intracerebral challenge with LCMV-WE, whereas transfused antibodies alone did not protect, and in some cases even enhanced, lethal lymphocytic choriomeningitis. Against the cytopathic vesicular stomatitis virus (VSV), specific CTLs and Th cells were induced in the presence of high titers of VSV-neutralizing antibodies after infection with 10(6) PFU of VSV, but not at lower virus doses. Taken together, preexistent protective antibody titers controlled infection but did not impair induction of protective T cell immunity. This is particularly relevant for noncytopathic virus infections since both virus-neutralizing antibodies and CTLs are essential for continuous virus control. Therefore, to vaccinate against such viruses parallel or sequential passive and active immunization may be a suitable vaccination strategy to combine advantages of both virus-neutralizing antibodies and CTLs.

Non-invasive detection of glycine as a biomarker of malignancy in childhood brain tumours using in-vivo 1H MRS at 1.5 tesla confirmed by ex-vivo high-resolution magic-angle spinning NMR.

Management of brain tumours in children would benefit from improved non-invasive diagnosis, characterisation and prognostic biomarkers. Metabolite profiles derived from in-vivo MRS have been shown to provide such information. Studies indicate that using optimum a priori information on metabolite contents in the construction of linear combination (LC) models of MR spectra leads to improved metabolite profile estimation. Glycine (Gly) is usually neglected in such models due to strong overlap with myo-inositol (mI) and a low concentration in normal brain. However, biological studies indicate that Gly is abundant in high-grade brain tumours. This study aimed to investigate the quantitation of Gly in paediatric brain tumours using MRS analysed by LCModel, and its potential as a non-invasive biomarker of malignancy. Single-voxel MRS was performed using PRESS (TR 1500 ms, TE 30 ms/135 ms) on a 1.5 T scanner. Forty-seven cases (18 high grade (HG), 17 low grade (LG), 12 ungraded) were retrospectively selected if both short-TE and long-TE MRS (n = 33) or short-TE MRS and high-resolution magic-angle spinning (HRMAS) of matched surgical samples (n = 15) were available. The inclusion of Gly in LCModel analyses led to significantly reduced fit residues for both short-TE and long-TE MRS (p < 0.05). The Gly concentrations estimated from short-TE MRS were significantly correlated with the long-TE values (R = 0.91, p < 0.001). The Gly concentration estimated by LCModel was significantly higher in HG versus LG tumours for both short-TE (p < 1e-6) and long-TE (p = 0.003) MRS. This was consistent with the HRMAS results, which showed a significantly higher normalised Gly concentration in HG tumours (p < 0.05) and a significant correlation with the normalised Gly concentration measured from short-TE in-vivo MRS (p < 0.05). This study suggests that glycine can be reliably detected in paediatric brain tumours using in-vivo MRS on standard clinical scanners and that it is a promising biomarker of tumour aggressiveness.

An investigation of WNT pathway activation and association with survival in central nervous system primitive neuroectodermal tumours (CNS PNET).

Central nervous system primitive neuroectodermal tumours (CNS PNET) are high-grade, predominantly paediatric, brain tumours. Previously they have been grouped with medulloblastomas owing to their histological similarities. The WNT/beta-catenin pathway has been implicated in many tumour types, including medulloblastoma. On pathway activation beta-catenin (CTNNB1) translocates to the nucleus, where it induces transcription of target genes. It is commonly upregulated in tumours by mutations in the key pathway components APC and CTNNB1. WNT/beta-catenin pathway status was investigated by immunohistochemical analysis of CTNNB1 and the pathway target cyclin D1 (CCND1) in 49 CNS PNETs and 46 medulloblastomas. The mutational status of APC and CTNNB1 (beta-catenin) was investigated in 33 CNS PNETs and 22 medulloblastomas. CTNNB1 nuclear localisation was seen in 36% of CNS PNETs and 27% of medulloblastomas. A significant correlation was found between CTNNB1 nuclear localisation and CCND1 levels. Mutations in CTNNB1 were identified in 4% of CNS PNETs and 20% of medulloblastomas. No mutations were identified in APC. A potential link between the level of nuclear staining and a better prognosis was identified in the CNS PNETs, suggesting that the extent of pathway activation is linked to outcome. The results suggest that the WNT/beta-catenin pathway plays an important role in the pathogenesis of CNS PNETs. However, activation is not caused by mutations in CTNNB1 or APC in the majority of CNS PNET cases.

Investigation of chromosome 1q reveals differential expression of members of the S100 family in clinical subgroups of intracranial paediatric ependymoma.

Gain of 1q is one of the most common alterations in cancer and has been associated with adverse clinical behaviour in ependymoma. The aim of this study was to investigate this region to gain insight into the role of 1q genes in intracranial paediatric ependymoma. To address this issue we generated profiles of eleven ependymoma, including two relapse pairs and seven primary tumours, using comparative genome hybridisation and serial analysis of gene expression. Analysis of 656 SAGE tags mapping to 1q identified CHI3L1 and S100A10 as the most upregulated genes in the relapse pair with de novo 1q gain upon recurrence. Moreover, three more members of the S100 family had distinct gene expression profiles in ependymoma. Candidates (CHI3L1, S100A10, S100A4, S100A6 and S100A2) were validated using immunohistochemistry on a tissue microarray of 74 paediatric ependymoma. In necrotic cases, CHI3L1 demonstrated a distinct staining pattern in tumour cells adjacent to the areas of necrosis. S100A6 significantly correlated with supratentorial tumours (P<0.001) and S100A4 with patients under the age of 3 years at diagnosis (P=0.038). In conclusion, this study provides evidence that S100A6 and S100A4 are differentially expressed in clinically relevant subgroups, and also demonstrates a link between CHI3L1 protein expression and necrosis in intracranial paediatric ependymoma.

Disseminated clustered juvenile xanthogranuloma: an unusual morphological variant of a common condition.

Juvenile xanthogranuloma (JXG) is a benign, self-healing non-Langerhans cell histiocytosis of unknown aetiology, most commonly occurring in infants and children. JXG is characterized by solitary or multiple yellowish cutaneous nodules, the two common clinical variants being a small nodular form and large nodular form, which frequently coexist. Unusual morphological presentations include keratotic, lichenoid, pedunculated, subcutaneous, clustered, plaque-like and giant lesions. We describe the first reported case of 'disseminated' clustered juvenile xanthogranuloma presenting in an infant.

Lymphatic vessel density in the neoplastic progression of Barrett's oesophagus to adenocarcinoma.

BACKGROUND: Oesophageal adenocarcinoma is an aggressive neoplasm with poor prognosis as a result of early lymph node metastasis. AIMS: To measure lymphatic vessel density (LVD) in the neoplastic progression from Barrett's metaplasia to adenocarcinoma and determine whether LVD can predict the risk of cancer. In addition, to correlate LVD with lymph node metastasis and assess whether LVD could be used as a prognostic indicator for outcome or survival. METHODS: LVD and microvascular density (MVD) were assessed after immunohistochemical staining of vessels in Barrett's metaplasia, dysplasia, and adenocarcinoma tissues and were correlated with clinicopathological features. RESULTS: LVD was significantly reduced in adenocarcinoma, being half that seen in normal stomach/oesophagus or metaplasia/dysplasia. LVD did not correlate with tumour grade, stage, or clinical outcome; however, patients who had either lymph node metastasis or invasion of tumour cells into peritumorous lymphatic vessels had a significantly worse overall survival. MVD was also assessed as a prognostic marker; its increase appeared to be linked more with the development of Barrett's metaplasia than adenocarcinoma. CONCLUSIONS: The reduction in lymphatic vessel numbers was not useful for determining disease outcome in the patient group studied. It is the entry of tumour cells into pre-existing peritumorous lymphatic vessels that confers a significantly worse overall survival.

Primary hepatic diffuse large B-cell lymphoma in a patient with chronic hepatitis C.

Epidemiological and experimental data suggest that the hepatitis C virus infection might be associated with the development of distinct types of non-Hodgkin's lymphomas. Here, we report a case of a patient with chronic hepatitis C and type II mixed cryoglobulinemia, who developed a primary hepatic non-Hodgkin's B-cell lymphoma. A diffuse, large B-cell lymphoma was diagnosed based on morphological, immunophenotypical and molecular genetic findings. Hepatitis C virus replication, as evaluated by strand-specific reverse transcriptase-polymerase chain reaction, was detected in the nonneoplastic liver, but not in the lymphomatous tissue. High grade non-Hodgkin's lymphomas, although rare complications, have to be considered as part of the spectrum of hepatitis C virus-related hepatic lesions.

Successful single-lung transplantation after paraquat intoxication.

Severe acute lung injury frequently develops after poisoning by paraquat, and respiratory failure is the major cause of death in patients surviving more than 2 days after ingestion. We describe a 17-year-old man with confirmed paraquat intoxication by lung and muscle biopsy, in whom single-lung transplantation was performed 44 days after poisoning for end-stage lung disease. The patient was discharged from the hospital 122 days after ingestion of paraquat and 88 days after lung transplantation. Before 1996, repeated lung transplantation had been performed for patients with terminal respiratory insufficiency due to paraquat toxicity, but all died. This patient survived probably because transplantation was performed very late after paraquat ingestion.

Epstein-Barr virus association in pediatric abdominal non-Hodgkin-lymphomas from Turkey.

Recent studies have shown marked geographic variation associated with Epstein-Barr virus (EBV) in pediatric Burkitt's lymphomas and Hodgkin's disease. In the present study we investigated 30 cases of pediatric extranodal high grade non-Hodgkin's lymphomas (NHL) from Turkey with an abdominal localisation. To classify them histologically and to determine the role of EBV in these lymphomas, immunohistochemistry (IHC), in situ hybridisation (ISH) and polymerase chain reaction (PCR) were used. Our series contained two histologic types: the Burkitt's or Burkitt's-like lymphomas (BL/BLL) and high grade NHL. They all were of the B cell type. The immunoglobulin heavy chain gene rearrangement revealed monoclonality in 87% of the BL/BLL cases, in contrast to the NHL cases, showing monoclonality in only 43% of the cases. EBV was found in tumor cells in a high frequency, independent of the histological subtype. EBV strains A and B were detected in 9 cases, with a preponderance of the B subtype (4/9 BL/BLL; 4/9 NHL). Our data suggest that high grade NHLs with abdominal localisation of Turkish children show the pattern of immunodeficient lymphomas to some extent.

Biliary migration of hepatocellular carcinoma fragment after transcatheter arterial chemoembolization therapy.

Occasional side-effects of transcatheter arterial chemoembolization therapy in hepatocellular carcinoma are essentially related to tissue necrosis. We report the case of a patient with hepatocellular carcinoma who experienced an acute common bile duct obstruction a few weeks after such a procedure, in the absence of obvious biliary tract invasion. An endoscopic sphincterotomy relieved the obstruction. At histology, the intra-biliary material was identified as a fragment of hepatocellular carcinoma. We discuss the causes of obstructive jaundice in the setting of hepatocellular carcinoma as well as in the specific situation of transcatheter arterial chemoembolization therapy.

Spontaneous hemorrhage of thymus and thymoma in adults.

Spontaneous hemorrhage from the thymus is extremely rare. In adults, it may occur in patients without underlying coagulopathy and mimic aortic dissection. To the best of our knowledge, only three previous adult cases have been reported in the English literature. This report presents two additional adult patients who were admitted in our institution with different clinical presentations of spontaneous thymic hemorrhage.

Feasibility of the new WHO classification of pulmonary neuroendocrine tumours.

Primary pulmonary neuroendocrine tumours present a heterogeneous group of tumours causing problems in diagnosis and treatment. The new WHO classification of lung tumours was published in 1999 in order to improve this situation by combining morphology, immunohistochemistry and clinical background for diagnosis. The aim of our study was to evaluate the feasibility of this classification and to discuss the consequences of modified diagnostic criteria. 50 cases of neuroendocrine tumours and 50 poorly differentiated lung tumours diagnosed in the years 1981-1994 were independently evaluated by three pathologists. The diagnosis of all 27 typical carcinoids (TC) was given by all authors, however, no unanimous agreement was achieved in one of three atypical carcinoids (AC) and two of four large cell neuroendocrine carcinomas (LCNEC). While typical and atypical carcinoids can be distinguished by the number of mitoses or presence of necrosis it was found that the most difficult diagnostic factor for large cell neuroendocrine carcinoma is the recognition of its light-microscopic neuroendocrine features. In consequence it must be distinguished not only from atypical carcinoid or small cell lung carcinoma (SCLC), but also from poorly differentiated carcinoma. Immunohistochemistry is important for the diagnosis of this entity but also for nonsmall cell lung carcinoma with neuroendocrine differentiation (of which 1 case was detected in our series) There was agreement on the diagnosis of small cell carcinomas in all but one case. The results indicate the excellent reproducibility of the WHO classification.

Intestinal obstruction caused by an ectopic fallopian tube in a child: case report and literature review.

The authors present the case of a prepubertal 14-year-old girl who was admitted for an acute abdominal pain, fever, and vomiting. She was in a poor general state, having recently suffered a weight loss of 5 kg. A plain abdominal x-ray disclosed signs of mechanical ileus. An abdominal ultrasound scan showed a normal uterus, a normal right-sided ovary, but no left ovary. An emergency laparoscopy found a normal uterus with complete absence of the left ovary and salpinx, the upper left dome of the uterus being smooth with no visible horn. The right ovary and salpinx were normal. Intestinal obstruction was caused by a strangulating cordlike structure of unclear origin. After converting to a laparotomy, we found an abnormal fallopian tube inserted in the left parieto-colic groove. The tube extended next on the lateral sigmoïd mesentery and wrapped itself around the ileum, provoking a local strangulation and an ischemic covered bowel perforation. The bowel perforation was treated by a segmental bowel resection. Careful dissection of the cordlike structure disclosed a true rudimentary fallopian tube with hypotrophic fimbriae and a small distal round structure containing ovarian tissue. These structures were removed entirely. A review of the literature on this rare situation is presented and discussed.

(1)H magnetic resonance spectroscopy in the diagnosis of paediatric low grade brain tumours.

INTRODUCTION: Low grade gliomas are the commonest brain tumours in children but present in a myriad of ways, each with its own treatment challenges. Conventional MRI scans play an important role in their management but have limited ability to identify likely clinical behaviour. The aim of this study is to investigate (1)H magnetic resonance spectroscopy (MRS) as a method for detecting differences between the various low grade gliomas and related tumours in children. PATIENTS AND METHODS: Short echo time single voxel (1)H MRS at 1.5 or 3.0 T was performed prior to treatment on children with low grade brain tumours at two centres and five MR scanners, 69 cases had data which passed quality control. MRS data was processed using LCModel to give mean spectra and metabolite concentrations which were compared using T-tests, ANOVA, Receiver Operator Characteristic curves and logistic regression in SPSS. RESULTS: Significant differences were found in concentrations of key metabolites between glioneuronal and glial tumours (T-test p<0.05) and between most of the individual histological subtypes of low grade gliomas. The discriminatory metabolites identified, such as choline and myoinositol, are known tumour biomarkers. In the set of pilocytic astrocytomas and unbiopsied optic pathway gliomas, significant differences (p<0.05, ANOVA) were found in metabolite profiles of tumours depending on location and patient neurofibromatosis type 1 status. Logistic regression analyses yielded equations which could be used to assess the probability of a tumour being of a specific type. CONCLUSIONS: MRS can detect subtle differences between low grade brain tumours in children and should form part of the clinical assessment of these tumours.

Complex patterns of chromosome 9 alterations including the p16INK4a locus in Wilms tumours.

BACKGROUND: Previous data implicating genetic and epigenetic events on chromosome 9, including the CDKN2A/2B locus, as molecular predictors of Wilms tumour relapse, have been conflicting. AIMS: To clarify this using genome-wide and focused molecular genetic analysis. METHODS: Microarray-based comparative genomic hybridisation (aCGH) using genome-wide coverage was applied to 76 favourable histology Wilms tumours. Additional investigation of the 9p21 locus was carried out using loss of heterozygosity (LOH) and fluorescence in situ hybridisation (FISH), as well as immunohistochemistry for CDKN2A/p16(INK4a) on a paediatric renal tumour tissue microarray. RESULTS: Approximately half of the tumours were found to show chromosome 9 copy number changes. Those cases which harboured alterations comprised at least four distinct patterns: gain of the entire chromosome, loss of 9p, gain of 9q34, or a more complex combination of gains/losses. None of these tumour groups showed any statistically significant correlation with clinicopathological variables. Deletion mapping of 9p by LOH revealed several regions of overlap, including the CDKN2A/2B locus in 4/34 (11.8%) tumours, which was confirmed to represent hemizygous deletions by FISH. CDKN2A/p16(INK4a) protein expression was predominantly negative in Wilms tumours as assessed by immunohistochemistry on a tissue array, reflecting the expression pattern in normal kidney. However, 38/236 (16.1%) non-anaplastic Wilms tumours, 4/9 (44.4%) anaplastic Wilms tumours, 5/7 (71.4%) rhabdoid tumours of the kidney, and 4/10 (40%) clear cell sarcomas of the kidney showed nuclear CDKN2A/p16(INK4a )immunoreactivity. CONCLUSIONS: These data reveal the complex nature of genetic alterations on chromosome 9 in Wilms tumours, but do not provide evidence for their involvement in or association with treatment failure.