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Wong N.A.C.S.,Royal Infirmary | Campbell F.,Royal Infirmary | Campbell F.,University of Liverpool | Shepherd N.A.,Royal Infirmary | Shepherd N.A.,Gloucestershire Cellular Pathology Laboratory
Histopathology | Year: 2015

Aims: Synovial sarcomas may arise within retroperitoneal or pelvic tissues or, more rarely, within the luminal gastrointestinal tract. This case series aims to demonstrate how such primary abdominal synovial sarcomas may particularly mimic gastrointestinal stromal tumour (GIST) on both morphological and immunohistochemical grounds. Methods and results: Four cases of primary abdominal synovial sarcoma were reviewed morphologically and with immunohistochemistry, fluorescence in-situ hybridization with an SS18 break-apart probe, and KIT/PDGFRA mutation analysis. The four patients comprised two males and two females, with a median age of 42 years (range: 17-59 years). Two synovial sarcomas arose within the stomach, one within the small-intestine mesentery, and the fourth within the retroperitoneum. All four tumours showed only a monophasic spindle cell component in the tissues available for review. All four tumours showed DOG1 immunopositivity, and three coexpressed CD117. Three tested cases did not show activating KIT or PDGFRA mutations, whereas all four cases showed chromosomal rearrangement of SS18. Conclusions: A diagnosis of synovial sarcoma should be considered particularly if an abdominal spindle cell neoplasm shows a haemangiopericytomatous pattern and diffuse CD99 and CD56 immunopositivity. A confident distinction between abdominal synovial sarcoma and GIST requires KIT/PDGFRA mutation analyses and specific molecular testing for synovial sarcoma. © 2014 John Wiley & Sons Ltd.

Shepherd N.A.,Gloucestershire Cellular Pathology Laboratory | Shepherd N.A.,Biophotonic Research Unit | Griggs R.K.L.,Biophotonic Research Unit
Modern Pathology | Year: 2015

The introduction of bowel cancer screening, in the United Kingdom, United States of America, and many other Western countries, has provided considerable interest and no little diagnostic consternation for pathologists. In the United Kingdom, the universal introduction of bowel cancer screening, initially by fecal occult blood testing and more recently by the introduction of flexible sigmoidoscopy, has provided four main areas of pathological diagnostic difficulty. This is the biopsy diagnosis of adenocarcinoma, serrated pathology, the diagnosis and management of polyp cancer, and, finally, the phenomenon of pseudoinvasion/epithelial misplacement (PEM), particularly in sigmoid colonic adenomatous polyps. The diagnostic difficulties associated with the latter phenomenon have provided particular problems that have led to the institution of a UK national 'Expert Board', comprising three pathologists, who adjudicate on difficult cases. The pathological features favoring PEM are well recognized but there is no doubt that there can be profound mimicry of adenocarcinoma, and, as yet, no adjunctive diagnostic tools have been developed to allow the differentiation in difficult cases. Research in this area is proceeding and some methodologies do show promise in this difficult diagnostic area. © 2015 USCAP, Inc.

Loughrey M.B.,Royal Victoria Hospital | Shepherd N.A.,Gloucestershire Cellular Pathology Laboratory
Histopathology | Year: 2015

Colorectal cancer screening is widely promulgated in many parts of the world and population screening is occurring in many countries, especially in western Europe. Although, intuitively, it might be thought that the pathology resulting from screening should be straightforward, being mainly that of polyp diagnosis and the biopsy diagnosis and staging of established adenocarcinoma, in fact experience has shown that there are several areas of considerable difficulty and controversy. In the UK somewhat different programmes, all based on faecal occult blood (FOB) screening, have been developed and each has generated similar pathological conundra. These include the biopsy diagnosis of adenocarcinoma, colorectal serrated pathology, the diagnosis and management of polyp cancers and last, but certainly not least, the phenomenon of the large sigmoid colonic adenomatous polyp with epithelial misplacement/pseudo-invasion. Polyp cancers provide especially difficult management conundra and discussion of that management within a multidisciplinary team-based management meeting is regarded as essential in the UK. Large adenomatous polyps of the sigmoid colon with epithelial misplacement are selected into FOB-based screening programmes and have provided extraordinary diagnostic challenges. Finally, the quality assurance procedures introduced for screening can ensure a considerable overall improvement in the quality of lower gastrointestinal tract pathological reporting. © 2015 John Wiley & Sons Ltd.

Bateman A.C.,Southampton General Hospital | Shepherd N.A.,Gloucestershire Cellular Pathology Laboratory
Journal of Clinical Pathology | Year: 2015

Bowel cancer screening programmes have highlighted to endoscopists and clinicians the spectrum of serrated colorectal lesions. One of the most significant developments has been the recognition that sessile serrated lesions (SSLs), while bearing histological resemblance to hyperplastic polyps (HPs), may be associated with the enhanced development of epithelial dysplasia and colorectal adenocarcinoma. Different minimum criteria exist for the diagnosis of SSLs and their differentiation from HPs. Furthermore, the spectrum of terminology used to describe the entire range of serrated lesions is wide. This variability has impaired interobserver agreement during their histopathological assessment. Here, we provide guidance for the histopathological reporting of serrated lesions, including a simplified nomenclature system. Essentially, we recommend use of the following terms: HP, SSL, SSL with dysplasia, traditional serrated adenoma (TSA) and mixed polyp. It is hoped that this standardisation of nomenclature will facilitate studies of the biological significance of serrated lesions in terms of the relative risk of disease progression.

Lloyd G.R.,Biophotonics Research Unit | Almond L.M.,Biophotonics Research Unit | Stone N.,University of Exeter | Shepherd N.,Gloucestershire Cellular Pathology Laboratory | And 4 more authors.
Analyst | Year: 2014

The application of semi-supervised methodology to improve the classification performance of a Raman spectroscopic probe for the diagnosis of oesophageal cancer is described. It is well known that gold standard histopathology diagnosis can be highly subjective, particularly for diseases which have several stages, such as cancer. A 'consensus' pathology decision can be obtained to ensure a robust gold standard by obtaining a diagnosis from several experts and samples are then only included in standard classification models if they have been assigned the same pathology by all experts. This can result in a significant number of samples that are excluded from the analysis as no consensus was reached. In this work semi-supervised methodology was used to extend Principal Component Analysis followed by Linear Discriminant Analysis (PCA-LDA) to incorporate samples without consensus pathology when discriminating between benign and oesophageal cancer specimens measured using a Raman endoscopic probe ex vivo. We demonstrate that a fully semi-supervised approach improved sensitivity and specificity from 73% and 78% (PCA-LDA) to 78% and 84% (semi-supervised) for discriminating between intestinal metaplasia and dysplasia and from 44% and 66% (PCA-LDA) to 63% and 72% (semi-supervised) when discriminating between intestinal metaplasia and low grade dysplasia. © 2014 The Royal Society of Chemistry.

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