title: Microinvasive germ cell tumor of the testis.
abstract: Microinvasive germ cell tumor (MGCT) consists of a limited number of malignant germ cells in the intertubular tissue of the testis. The cells have large nuclei, prominent nucleoli, abundant clear cytoplasm, and distinct cellular borders in hematoxylin and eosin staining. MGCT can be the first stage of malignancy in the development of testicular germ cell tumor (TGCT). Biopsies from men with maldescended testes have been reported to contain intratubular germ cell neoplasia, unclassified (IGCN) and MGCT in 1.8% of the examined cases (95% CI 0.5-4.6%). MGCT has also been found in testes of subfertile men and in the contralateral testis of patients with TGCT. MGCT is a frequent finding (19%) in the testicular tissue adjacent to an overt TGCT. Men with a high risk of TGCT may gain from screening for precursor lesions of TGCT with ultrasonography of the testes followed by a testicular biopsy if suspicious abnormalities are found: Treatment is high-voltage radiotherapy for intratubular germ cell neoplasia (IGCN), and orchidectomy for MGCT and germ cell tumor in situ, either intratubular seminoma or intratubular embryonal carcinoma. After local treatment, patients with precursor lesions can be followed with a surveillance program. The mRNA levels of invasion-related genes were evaluated based on a DNA microarray data set, and we found two gene abnormalities most relevant for the invasion of malignant germ cells: matrix metalloproteinase 9 (MMP9) and plasminogen activator, urokinase (PLAU) genes were up-regulated in a study comparing tissue samples of TGCT and IGCN.
authors.affiliation: Center of Tobacco Control Research, Birkevej 17, 5230 Odense, Denmark. feve@post5.tele.dk
authors.forename: Finn Edler
authors.initials: FE
authors.lastname: von Eyben
authors.forename: Grete Krag
authors.initials: GK
authors.lastname: Jacobsen
authors.forename: Rolf Inge
authors.initials: RI
authors.lastname: Skotheim
mesh_terms: D006801:Humans; D008297:Male; D009373:Neoplasms, Germ Cell and Embryonal; D011230:Precancerous Conditions; D013736:Testicular Neoplasms