title: Ovarian-type epithelial tumours of the testis: immunohistochemical and molecular analysis of two serous borderline tumours of the testis.
abstract: Tumours of ovarian-epithelial type of the testis, including serous borderline tumours, represent very rare entities. They are identical to the surface epithelial tumours of the ovary and have been reported in patients from 14 to 68 years of age. We describe two cases of a 46- and a 39-year old man with incidental findings of intratesticular masses of the left respectively right testis. Under the assumption of a malignant testicular tumour the patients were subjected to inguinal orchiectomy. Histologically, the tumours were identical to their ovarian counterparts: They showed a cystic configuration with a fibrous wall and irregular papillary structures lined by partially multistratified columnar cells and areas of hobnail cells. Furthermore, there was mild cytological atypia with a proliferative activity of below 5% as proved by Ki67 staining; mitoses could not be detected. Immunohistochemically, the tumour cells displayed expression of pan-cytokeratin AE3, progesterone receptor, Wilms' tumour protein (WT1), and PAX8 (Paired box gene 8). Estrogen receptor was expressed in one case. Octamer-binding transcription factor-4 (OCT4), calretinin, thrombomodulin, and D2-40 were not expressed. Mutation testing of BRAF revealed a BRAF V600E mutation in one case, while testing for KRAS mutations proved to be negative in both. The BRAF mutated tumour showed strong cytosolic and membranous positivity for B-Raf also on immunohistochemical analysis. Comparative genomic hybridization of one case could not reveal any chromosomal aberrations.
authors.affiliation: Institute of Pathology, University Medical Center, Univeristy of Göttingen, Göttingen, Germany. tobias.buerger@med.uni-goettingen.de.
authors.forename: Tobias
authors.initials: T
authors.lastname: Bürger
authors.affiliation: Institute of Pathology, University Medical Center, Univeristy of Göttingen, Göttingen, Germany. hans-ulrich.schildhaus@med.uni-goettingen.de.
authors.forename: Hans-Ulrich
authors.initials: HU
authors.lastname: Schildhaus
authors.affiliation: Praxisgemeinschaft Pathologie, Düsseldorf/Gummersbach, Germany. inniger@kkh-gummersbach.de.
authors.forename: Reinhard
authors.initials: R
authors.lastname: Inniger
authors.affiliation: Praxisgemeinschaft Pathologie, Düsseldorf/Gummersbach, Germany. jojo.hansen@web.de.
authors.forename: Joachim
authors.initials: J
authors.lastname: Hansen
authors.affiliation: Department of Urology, Catholic Clinics Oberberg, Engelskirchen, Germany. peter.mayer@k-k-o.de.
authors.forename: Peter
authors.initials: P
authors.lastname: Mayer
authors.affiliation: Gemeinschaftspraxis Pathologie, Starnberg, Germany. S.Schweyer@pathologie-starnberg.de.
authors.forename: Stefan
authors.initials: S
authors.lastname: Schweyer
authors.affiliation: Institute of Pathology, University Medical Center, Univeristy of Göttingen, Göttingen, Germany. hradzun@med.uni-goettingen.de.
authors.forename: Heinz Joachim
authors.initials: HJ
authors.lastname: Radzun
authors.affiliation: Institute of Pathology, University Medical Center, Univeristy of Göttingen, Göttingen, Germany. philipp.stroebel@med.uni-goettingen.de.
authors.forename: Philipp
authors.initials: P
authors.lastname: Ströbel
authors.affiliation: Institute of Pathology, University Medical Center, Univeristy of Göttingen, Göttingen, Germany. Felix.bremmer@med.uni-goettingen.de.
authors.forename: Felix
authors.initials: F
authors.lastname: Bremmer
mesh_terms: D000328:Adult; D014408:Biomarkers, Tumor / Q000032:analysis; D018293:Cystadenoma, Serous / Q000235:genetics / Q000473:pathology*; D004252:DNA Mutational Analysis; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics; D016283:Proto-Oncogene Proteins p21(ras) / Q000235:genetics; D013736:Testicular Neoplasms / Q000235:genetics / Q000473:pathology*
chemical_list: D014408:Biomarkers, Tumor; C117307:KRAS protein, human; C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf; D016283:Proto-Oncogene Proteins p21(ras)