O253 Dimensional Pathology with Virtual SlidesDTreanor 1 , K Brabazon 2 , D Magee 2 ,PQuirke 11 Pathology and Tumour Biology, <strong>Leeds</strong> Institute <strong>of</strong> Molecular Medicine,University <strong>of</strong> <strong>Leeds</strong>, 2 School <strong>of</strong> Computing, University <strong>of</strong> <strong>Leeds</strong>Visualisation <strong>of</strong> tissue in 3 dimensions (3D) has many potential uses in tissuebased research. Previously, obtaining 3D models <strong>of</strong> tissue has been a laboriousprocess requiring manual photomicrography <strong>of</strong> standard pathology slides or theuse <strong>of</strong> alternative acquisition methods which result in a loss <strong>of</strong> cellularinformation.We describe a method for 3D reconstruction <strong>of</strong> tissue using virtual slides whichallows reconstruction <strong>of</strong> structures at high resolution (that <strong>of</strong> tissue microarchitecture)using standard pathology slides. <strong>The</strong> method uses novel customdevelopeds<strong>of</strong>tware to align (register) virtual slides and extract 3D informationfrom them.Our methods differ from previous research in this area in that they allow a highthroughputprocess minimising the need for manual intervention. Virtual slidescan be scanned automatically under standard scanning conditions, easilyproducing sequential images to use in 3D construction. Once low resolutionimages have been registered, a further novel aspect <strong>of</strong> our approach is that smalltissue micro-architectural details can be reconstructed in 3D from any part <strong>of</strong>the registered 3D volume without the need to re-scan the area at higherresolution.Using this method we have produced demonstrator 3D reconstructions <strong>of</strong> amouse embryo and cirrhotic human liver with 50-200 sections, and an entireglomerulus with over 200 semi-thin sections.This technique can be used to study disease processes in 3 dimensions usingstandard histochemical and immunohistochemical techniques.O27Immunohistochemical Expression <strong>of</strong> CD10 in Cutaneous Basaland Squamous Cell CarcinomaHAiad 1 , H Hanout 11 Min<strong>of</strong>yia University, Faculty <strong>of</strong> Medicine, Pathology DepartmentCD10 is a zinc-dependent metallopeptidase. CD10 expression has beeninvestigated in some cutaneous tumours, however, data regarding its expressionin cutanous epithelial neoplasms are very limited. We aimed to examine theimmunohistochemical expression <strong>of</strong> CD10 in basal cell carcinoma (BCC)(21cases) and squamous cell carcinoma (SCC) (16 cases). Positive CD10staining was identified as brown cytoplasmic with or without cell membranestaining. In all the 16 SCC cases, tumour cells failed to stain to CD10 incontrast to the stromal cells that showed CD10 expression in 13 cases (81%). InBCC cases, the expression <strong>of</strong> CD10 was noted in tumour cells in 47.6 % andstromal cells in 95.24%. Most <strong>of</strong> CD10+ 7/10 BCC showed well-circumscribeddeep margin, however, most <strong>of</strong> CD10- cases 9/11 showed infiltrating base(P=0.030). BCCs with infiltrating deep margins (12 cases) tended to showCD10 negative basaloid cells (9/12) and CD10 positive stromal cells (12/12)(P=0.0003). <strong>The</strong>re was no significant relation between CD10 and otherclinicopathological factors in SCC or BCC. From our results we suggest thatCD10 might be a useful immunohistochemical marker to differentiate betweenBCC and SCC. At least, if tumour cells were CD10 positive, this would favorBCC over SCC. Absence <strong>of</strong> CD10 in all the SCC and in infiltrating BCCtogether with its overexpression in the surrounding stromal cells might conferinvasive properties to such tumours. However, its relation to other poorprognostic factors needs larger studies to be confirmed.O26<strong>The</strong> Immunohistochemical Differentiation Between MetastaticBreast Cancer and Malignant Pleural MesotheliomaGR Powell 1 , WR Roche 11 School <strong>of</strong> Medicine, University <strong>of</strong> SouthamptonBackground. <strong>The</strong> mesothelioma specific markers, calretinin and cytokeratin5/6, and the breast cancer marker oestrogen receptor are frequently used todifferentiate metastatic breast cancer in the pleura from mesothelioma.However, some metastatic breast cancers may mimic the immunohistochemicalpr<strong>of</strong>ile <strong>of</strong> mesothelioma. <strong>The</strong> objectives <strong>of</strong> this study were to firstly examinethe expression <strong>of</strong> these markers in invasive breast cancer, and secondly, to auditthe immunostaining <strong>of</strong> archived pleural malignancies.Methods. 64 cases <strong>of</strong> primary invasive breast cancer were immunostained forcalretinin. Tumours that expressed calretinin were additionally immunostainedfor cytokeratin 5/6. Pleural malignancies diagnosed in biopsies from patientswith a history <strong>of</strong> breast cancer but without asbestos exposure were retrieved andre-examined.Results. 5 cases <strong>of</strong> breast cancer (8%) expressed calretinin and 4 <strong>of</strong> these 5tumours also expressed cytokeratin 5/6. <strong>The</strong> pattern <strong>of</strong> expression <strong>of</strong> bothmarkers was indistinguishable from that seen in epithelioid mesothelioma. All<strong>of</strong> the 5 tumours were Blooms grade 3 invasive ductal carcinomas and noneexpressed oestrogen receptor. <strong>The</strong> audit found 2 patients had been diagnosedwith mesothelioma despite a past history <strong>of</strong> breast cancer and no history <strong>of</strong>asbestos exposure. <strong>The</strong>se tumours expressed calretinin but not oestrogenreceptor.Conclusions. Concurrent expression <strong>of</strong> calretinin and cytokeratin 5/6 andnegative expression <strong>of</strong> oestrogen receptor in high-grade breast tumours is apotential diagnostic problem in pleural biopsies. This may lead to patients withmetastatic breast cancer being misdiagnosed with malignant mesothelioma.O28Genomic Analysis <strong>of</strong> Follicular Lymphoma SubgroupsD Marjenberg 1 , PJ Batstone 2 , KE Robertson 1 ,DA Levison 1 ,JR Goodlad 1,31 Division <strong>of</strong> Pathology & Neuroscience, University <strong>of</strong> Dundee, Dundee,UK, 2 Department <strong>of</strong> Pathology, Raigmore Hospital, Inverness, UK,3 Department <strong>of</strong> Pathology, Western General Hospital, Edinburgh, UKBackground: <strong>The</strong> characteristic genetic feature <strong>of</strong> follicular lymphoma (FL) is at(14;18)(q32;q21) present in 85% <strong>of</strong> cases, leading to inhibition <strong>of</strong> apoptosisand an indolent phenotype. However, recent studies suggest that there may be at(14;18)(q32;q21)-negative subgroup <strong>of</strong> FL that is more closely related to, andbetter treated as, diffuse large B-cell lymphoma (DLBCL). We sought todetermine if there were genetic abnormalities to support such a hypothesis, bystudying the genomic pr<strong>of</strong>ile <strong>of</strong> a large cohort <strong>of</strong> t(14;18)(q32;q21)-positive andnegative lymphomas <strong>of</strong> follicle centre origin.Methods: A combination <strong>of</strong> morphology, immunohistochemistry andfluorescence in situ hybridization was used to identify groups <strong>of</strong> translocationpositive and negative FL, and DLBCL <strong>of</strong> germinal centre type. Karyotypicanalysis (N=100) and microarray-based comparative genomic hybridisation(aCGH) (N=40) were then used to determine the chromosomal aberrations ineach group.Results: t(14;18)(q32;q21)-positive and negative FL were found to havealmost identical genetic pr<strong>of</strong>iles, with the exception <strong>of</strong> a loss <strong>of</strong> 1p36 found in70% <strong>of</strong> t(14;18)(q32;q21)-positive FL but only 10% <strong>of</strong> t(14;18)(q32;q21)-negative FL. A greater difference in chromosomal pr<strong>of</strong>iles was witnessed whent(14;18)(q32;q21) negative FL was compared with the cohort <strong>of</strong> DLBCL.Conclusion: <strong>The</strong> results indicate that t(14;18)(q32;q21)-negative FL isgenetically more closely related to t(14;18)(q32;q21)-positive FL than toDLBCL. Further investigations are required to determine whether there aremore subtle genetic abnormalities or epigenetic phenomena that might explainthe pathogenesis <strong>of</strong> t(14;18)(q32;q21)-negative FL and account for theaggressive behaviour <strong>of</strong> a subset <strong>of</strong> cases.84 <strong>Summer</strong> <strong>Meeting</strong> (194 th ) 1–4 July <strong>2008</strong> Scientific Programme
O29Genomic instability <strong>of</strong> haemopoietic cells in newly diagnosedMyelodysplastic syndrome (MDS) and Acute myeloidLeukemia (AML) assessed by G-banding, multicolour FISHand array-CGHM Yusuf 1 , N Rooney 2 , A Whiteway 2 ,TDavies 2 , M Williams 2 ,NAffara 3 , R Furlong 3 ,PCase 11 University <strong>of</strong> Bristol, 2 North Bristol NHS Trust, 3 University <strong>of</strong> CambridgeWe hypothesised that if haemopoietic cells are genetically unstable duringMDS-AML transformation in-vivo, that this instability might express itself intissue culture during cell divisions, in-vitro, over 4 days. <strong>The</strong>refore we havefollowed bone marrow cells from 12 patients looking at different cell divisions(0hrs, 24hrs, 48hrs and 96hrs) in tissue culture. We employed conventionalcytogenetics, multicolour FISH and array based comparative genomichybridization (array-CGH) to identify all aberrations and to search for genomicimbalances. We detected copy number changes by array-CGH even in patientswho had a normal karyotype. Data from 9 patients (each with data from 0hrs,24hrs, 48hrs and 96hrs) were grouped and a mixed model ANOVA wasapplied. 180 clones showed a significant and progressive change (p
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