title: Light and electron microscopy of the pagetoid spread of germ cell carcinoma in the rete testis: morphologic evidence suggestive of field effect as a mechanism of tumor spread.
abstract: The purpose of this study is to investigate the mechanism of tumor spread in the pagetoid spread of germ cell tumors in the rete testis (PSRT). Twenty consecutive cases of germ cell tumor of the testis (9 seminomas, 3 embryonal carcinomas, and 8 teratocarcinomas) were retrieved to identify the cases with PSRT. The areas of pagetoid spread were examined by the serial sectioning of the entire thickness of the tissue block. Available fresh tissue was submitted for electron microscopic study. Ten cases were associated with PSRT and had focal or extensive areas of intratubular germ cell neoplasia (IGCN) in the proximity of the tumor and the rete testis (RT). In the remaining 10 cases, 6 were associated with IGCN distant from the RT and the last 4 were not associated with IGCN. Seminiferous tubules with IGCN were seen connecting with the RT with pagetoid spread. Isolated single intraepithelial tumor cells also were identified at the periphery of the areas with PSRT. Electron microscopic study of the RT of 4 cases with PSRT (2 seminomas, 1 embryonal carcinoma, and 1 teratocarcinoma) revealed desmosome-type junctions between tumor cells with RT epithelial cells. Direct tumor expansion and cell motility as mechanisms of tumor spread in PSRT does not explain the presence of isolated cells and desmosome-type junctions of the tumor cells as demonstrated in this study. The authors believe that the field effect plays an important part in the pathogenesis of this pagetoid spread in the RT. It is likely that this field effect is induced by the germ cell tumor and is operated through the immature germ cells or undifferentiated epithelial cells in the RT adjacent to the tumor cells.
authors.affiliation: Division of Anatomical Pathology, Department of Laboratory Medicine, The Ottawa Hospital, Ontario, Canada. ktmai@civich.ottawa.on.ca
authors.forename: K T
authors.initials: KT
authors.lastname: Mai
authors.forename: H M
authors.initials: HM
authors.lastname: Yazdi
authors.forename: P
authors.initials: P
authors.lastname: Rippstein
mesh_terms: D018236:Carcinoma, Embryonal / Q000473:pathology / Q000648:ultrastructure; D002471:Cell Transformation, Neoplastic / Q000648:ultrastructure; D003896:Desmosomes / Q000648:ultrastructure; D006801:Humans; D008297:Male; D008854:Microscopy, Electron; D009361:Neoplasm Invasiveness / Q000473:pathology / Q000648:ultrastructure; D009373:Neoplasms, Germ Cell and Embryonal / Q000473:pathology* / Q000648:ultrastructure; D010145:Paget Disease, Extramammary / Q000209:etiology / Q000473:pathology*; D012152:Rete Testis / Q000473:pathology* / Q000648:ultrastructure; D018239:Seminoma / Q000473:pathology / Q000648:ultrastructure; D018243:Teratocarcinoma / Q000473:pathology / Q000648:ultrastructure; D013736:Testicular Neoplasms / Q000209:etiology / Q000473:pathology* / Q000648:ultrastructure