2008 Summer Meeting - Leeds - The Pathological Society of Great ...

P95Ovarian Neuroblastoma Arising Within a Mature CysticTeratoma: A Rare Pathological EntityNP West 1 , P Roberts 2 , I Richmond 3 , C Cullinane 1 , N Wilkinson 11 Department of Histopathology, Leeds Teaching Hospitals Trust, UK,2 Cytogenetics Unit, St. James's University Hospital, Leeds, UK,3 Department of Cellular Pathology, Hull Royal Infirmary, UKMature cystic teratomata (MCT) are common ovarian neoplasms whichundergo malignant transformation in 1-2% of cases with squamous cellcarcinomas accounting for the vast majority. Maligant neural tumours arisingfrom MCT are exceptionally rare. Here we describe a case of neuroblastomadeveloping within an ovarian teratoma in a 30 year old female.Macroscopically the specimen was received from theatre in piecescontaining part of a cyst wall lined by hair bearing skin. Solid areas wereidentified showing a variegated appearance with firm white tumour and foci ofhaemorrhage.Histologically the cyst was lined by stratified squamous epithelium withappendigeal structures, adipose tissue and mature neural elements. The solidareas consisted of sheets and nests of small pleomorphic blue cells,neurofibrillary stroma, focal Homer-Wright rosettes and multifocal anaplasiawith bizarre uninucleated and multinucleated giant cells. No ganglion celldifferentiation was identified.Immunohistochemistry showed these cells to be neuroblastic in originbeing positive for CD56, synaptophysin and NB84. The tumour was classifiedaccording to the International Neuroblastoma Pathology Classification (INPC)as stroma poor with an intermediate MKI (mitotic-karyorrhecticindex). Fluorescent in-situ hybridization was carried out on paraffin sectionsand showed N-myc amplification and a relative 17q gain in the neuroblastictumour.Only a handful of cases of neuroblastoma arising in ovarian MCT havebeen described to date and all previous reports were in patients under 20 yearsof age. According to the age-linked INPC, this tumour is thought to carry anunfavourable prognosis.P97Clear Cell Carcinomas of the Female Genital Tract- AClinicopathological Analysis of 73 CasesP Bhagwat 1 , M Butler-Manuel 2 ,ATaylor 2 ,SEssepah 3 ,S Di Palma 1 .1 Histopathology,Royal Surrey County Hospital, Guildford, Surrey,2 Surgery, Royal Surrey County Hospital, Guildford, Surrey, 3 MedicalOncology, Royal Surrey County Hospital, Guildford, SurreyClear cell carcinomas (CCC) arise from the female genital tract and from theperitoneum. Studies indicate that they lack oestrogen receptors. The geneticassociation for these tumours have been described, and various associationshave been proposed ranging from BRCA1, p53 to HER2-neu. These tumours inparticular have a distinct molecular signature with simple hierarchicalclustering.We have retrieved 73 consecutive cases from archives of RoyalSurrey County Hospital, Guildford from 1997 to present. Surgical pathologyreports and original histology slides have been retrieved. The aim of this studyis to update our knowledge of these tumours in view of gene expression profiledata suggesting a “distinct” molecular signature of clear cell carcinoma.Immunohistochemical staining for oestrogen receptors, both alpha and beta,androgen receptors, Her-2 protein (4B5) and Her2 gene, MIB-1, p53, CD 10andp16 are being performed at Royal Surrey County Hospital. Amplification bysilver in situ hybridisation (SISH) techniques is also in progress.P96Morules in endometrioid proliferations of the uterus andovary consistently express the intestinal transcription factorCDX2O Houghton 1 , WG McCluggage 1 , LE Connolly 11 Royal Group of Hospitals, BelfastAims: To undertake an immunohistochemical analysis of squamous elements inendometrioid proliferations of the uterus and ovary and to compare theimmunophenotype of typical squamous elements and so-called squamousmorules.Methods+Results: Cases of uterine or ovarian endometrioid glandular lesionswith squamous elements were stained with CDX2, catenin, ER, CD10, p63and highmolecularweight cytokeratin LP34. Thirteen cases had typicalsquamous elements and 18 cases morules. Morules typically exhibited diffusenuclear CDX2 and catenin immunoreactivity and were positive with CD10and LP34. They were usually ER and p63 negative. In contrast, typicalsquamous elements were usually positive with ER, CD10, p63 and LP34. Theywere usually CDX2 negative or focally positive and exhibited no nuclearstaining with catenin. Ten endometrioid carcinomas not exhibiting squamousdifferentiation were stained with CDX2; one was focally positive. Electronmicroscopy in two ovarian endometrioid adenocarcinomas with extensivemorular differentiation showed that the morules exhibited epithelial features butno overt evidence of squamous differentiation.Conclusions: Typical squamous elements and morules have an overlapping butdiffering immunophenotype. Morules exhibit no firm immunohistochemical orultrastructural evidence of squamous differentiation, although immaturesquamous differentiation cannot be excluded. Nuclear catenin positivity is inkeeping with the observation that endometrioid glandular lesions with morulesare often associated with catenin gene mutation. The explanation for diffusenuclear positivity with the intestinal transcription factor CDX2 in morules is notclear but may be a result of overexpression of nuclear catenin. We suggest thatthe term morular metaplasia is used instead of squamous morules.P98Increased p16 Expression in High Grade Serous CarcinomaCompared to Other Morphological Types of OvarianCarcinomaV Phillips 1 , PKelly 2 , WG McCluggage 11 Dept. of Histopathology, Royal Group of Hospitals, Belfast, 2 Dept. ofHistopathology, Belfast City HospitalIt has been previously shown that p16 is overexpressed in high grade serouscarcinoma but there has been little detailed comparison of p16 expression incommon types of ovarian carcinoma. This study aimed to compare p16expression in ovarian carcinomas of serous, endometrioid, clear cell andmucinous type and ascertain whether high expression in a primary ovariancarcinoma is specific for a serous neoplasm. Problematic cases which aredifficult to type, such as poorly differentiated and undifferentiated carcinomasand serous carcinomas with clear cells were also included. In these problematicgroups, p16 expression was compared with that of WT1, which is known to berelatively specific for serous phenotype. Cases of ovarian high grade serous(n=38), endometrioid (n=15), clear cell (n=12) and mucinous carcinomas(n=10) were stained with p16. Cases were scored with respect to distribution ofimmunoreactivity and intensity, and an immunohistochemical composite scorecalculated. Serous carcinomas typically exhibited high p16 expression; therewas statistically significant higher p16 expression in serous carcinomascompared to other morphological types. High p16 and WT1 expression wasidentified in undifferentiated carcinomas and in serous carcinomas with clearcells, suggesting that these represent variants of serous carcinoma. We havedemonstrated that p16 is highly expressed in high grade serous carcinomascompared to other morphological types of ovarian carcinoma. This may beuseful, in conjunction with WT1, in the diagnosis of problematic cases. p16may be involved in the pathogenesis of high grade ovarian serous carcinomas,through inactivation of retinoblastoma protein.56 Summer Meeting (194 th ) 1–4 July 2008 Scientific Programme