D Rampling

Histopathological reporting of paediatric cutaneous vascular anomalies in relation to proposed multidisciplinary classification system

Background: The terminology applied to vascular anomalies has been variable in previously published literature making interpretation suboptimal. The International Society for the Study of Vascular Anomalies (ISSVA) has proposed a revised classification based on clinical features and histopathological findings. This classification is increasingly being accepted as clinically useful and a platform for future studies. Aims: To examine the extent to which the ISSVA classification can be practically applied to diagnostic histopathological specimens. Methods: Cutaneous vascular lesions received in a single paediatric pathology unit during a 2-year period (2004–5) were reviewed, including glucose transporter protein 1 (GLUT1) immunostaining where required, and lesions were reclassified according to the ISSVA classification. Results: 144 specimens were identified. Appropriate full clinical information was provided in only 17% of cases at submission. Infantile haemangiomas comprised 46% of cases, 18% of which were regressive type, initially inaccurately identified as vascular malformations before GLUT1 immunostaining. 30% of lymphatic malformations and all lymphovenous malformations were previously classified as vascular malformations, not otherwise specified. Conclusions: The ISSVA classification of vascular anomalies provides a useful framework for histopathologists to classify vascular anomalies. However, meaningful and appropriate use of such a system is dependent on the adequacy of clinical information provided and routine use of immunohistochemical markers.

Gains of Chromosome 8 in Pleuropulmonary Blastomas of Childhood

Vargas et al. [1] recently reported their experience with two cases of childhood pleuropulmonary blastomas (PPB), in addition to several further cases from the literature, with regard to the presence of chromosome 8 gains detected by fluorescence in situ hybridization (FISH) and karyotyping. We wish to add further information from an additional four unreported cases of childhood PPB in which paraffin-embedded and freshfrozen tissues were available for study. In each case, tissue sections stained with hematoxylin & eosin were assessed to examine the morphological features and interphase FISH was carried out using a chromosome 7/8 probe cocktail. The clinical details and FISH results are summarized in Table 1. In all cases, sections demonstrated the predominant appearance of sheets of blastema composed of small round blue cells, with a variably pleomorphic spindle cell component and cystic areas. In three of the four cases, trisomy 8 was detected by FISH. The other case demonstrated apparent tetraploidy, with four copies present per cell of the markers examined. In combination with the results presented by Vargas et al. [1], all 15 cases of PPB appear to show chromosome 8 gains, however, several additional chromosomal abnormalities may be present, including apparent tetraploidy. Our results further support the hypothesis that childhood PPB demonstrate characteristic clinicopathological diagnostic features. The finding that chromosome 8 gains are present in the majority, if not all, cases raises the issue of the diagnostic use of interphase FISH in such cases. Although the finding of trisomy 8 is not specific for this tumor, being found in several other pediatric solid malignancies, as stated in the previous report [1], in clinical practice, the finding of trisomy 8 in a childhood thoracic tumor with compatible morphological features lends considerable support to the diagnosis of PPB. Interphase FISH for precisely this purpose has been employed by us and may be particularly useful in the context of biopsy interpretation in which the architectural features and biphasic nature of the lesion may not be immediately apparent on routine morphological sections.

Stem cell transplantation for tetratricopeptide repeat domain 7A deficiency: long-term follow-up.

To the editor: Mutations in the tetratricopeptide repeat domain 7A ( TTC7A) gene cause a severe form of very early onset inflammatory bowel disease (VEOIBD).[1][1] TTC7A has a crucial role in chaperoning the enzyme phosphatidylinositol-4-kinase-3-α from the trans-Golgi apparatus to the plasma

Rapid and accurate determination of MYCN copy number and 1p deletion in neuroblastoma by quantitative PCR.

MYCN amplification and 1p36 deletion are adverse prognostic factors in neuroblastoma, and rapid accurate determination of MYCN amplification is essential for risk stratification. MYCN copy number and 1p36 deletion status were determined by fluorescence in situ hybridization (FISH) and real time PCR in a diagnostic pathology laboratory setting on 35 consecutive patients with neuroblastoma. The PCR technique was technically successful in all cases and results were generally available within 24 hr of biospy. There was no discordance between FISH and PCR results. Real time PCR is a reliable, accurate, and simple technique that can be applied to small neuroblastoma biopsies allowing rapid diagnosis.

Abstract LB-328: SHP-1, p53 and Y674/Y675-phosphorylated-trkA: a molecular pathway and prognostic marker for neuroblastoma

Proceedings: AACR Annual Meeting 2014; April 5-9, 2014; San Diego, CA Neuroblastomas, which have sympathoadrenergic origin, are the most frequent childhood extracranial tumors. Good prognosis tumors (favourable cytogenetics, differentiated) express nerve growth factor (NGF) receptor tyrosine kinase trkA, whereas poor prognosis neuroblastomas (adverse cytogenetics, Myc amplification, poor differentiation) express neurotrophin receptor tyrosine kinase trkB. On NGF stimulation, trkA is activated by tyrosine phosphorylation and outcome is cell/tissue-dependent, and can signal for differentiation. We have shown that in rat sympathoadrenergic PC12 cells, wild-type (wt)p53 expression induces trkA tyrosine phosphorylation and trkA dependent signalling, promoting their NGF independent differentiation. In breast cancer tumors and neuroblastomas, high trkA levels are associated with good prognosis. In both tumour types the p53 mutation incidence is 20-25%. The tyrosine phosphatase SHP-1 dephosphorylates trkA tyrosines 674/675(Y674/Y675). We have shown that in breast cancer wt-p53 represses SHP-1 expression and induces trkA-Y674/Y675 phosphorylation, leading to NGF-independent trkA activation. This signals to suppress breast cancer proliferation by promoting cell-cycle arrest. Furthermore, in breast cancer, coexpression of phosphorylated trkA-Y674/Y675, wt-p53 and low SHP-1 levels, correlates with prolonged 15 years disease free survival (DFS). Our experiments provide a mechanism for trkA expression correlation with good prognosis in breast cancer and emphasise the importance of this mechanism in cancer. As neuroblastomas contain different cell populations, it has been difficult to identify prognostic biomarkers that would predict patient outcome. We have shown that wt-p53 repression of SHP-1 leads to trkA-Y674/Y675 phosphorylation and neuroblastoma differentiation. Neuroblastoma differentiation is associated with improved DFS. Thus we asked if, the presence of wt-p53 and SHP-1 downregulation, together with phosphorylated trkA, in neuroblastoma samples, correlates with favourable outcome. Confirmation of this mechanism would validate new molecular targets for neuroblastoma. Neuroblastoma arrays containing 169 samples were stained for p53, SHP1 and phosphorylated trkA-Y674/Y675 expression. Multivariate analysis showed low p53 levels associated with 65% 5 years DFS (hazard-ratio (HR)=0.35, p=0.09), whereas, high SHP1 expression was associated with a worse DFS (HR=1.37, p=0.028). Phosphorylated trkA-Y674/Y675 expression correlated with 88% 5 years DFS (HR=0.12, (p=0.001)). As differentiation is associated with improved survival, the differentiation markers MAP2 and Vimentin were included. Expression of MAP2 and Vimentin correlated with good DFS (71% (HR=0.29, p=0.027) and 35% (HR=0.65, p=0.014)). Myc amplification correlated with reduced DFS (HR=4.84, p=0.001) as expected. Importantly, multivariate-analysis of patients with tumors harbouring p53 together with high SHP-1 levels and phosphorylated trkA-Y674/Y675 showed 69% 5 years DFS (HR=0.29, p=0.001). Favourable DFS was seen when MAP2 and Vimentin (HR=0.53, p=0.032 and HR=0.51, p=0035) were included. Further statistical analysis which considers tumor cytogenetics will be presented. Our results will allow refinement of the prognostic tools available for neuroblastoma with direct impact on child healthcare. Citation Format: Gehad Youssef, Cheryl Gillet, Dyanne Rampling, Mirza Chagtay, Alex Virasami, Neil Sebire, John Anderson, Ximena Montano. SHP-1, p53 and Y674/Y675-phosphorylated-trkA: a molecular pathway and prognostic marker for neuroblastoma. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-328. doi:10.1158/1538-7445.AM2014-LB-328