title: Chromosome 12p abnormalities and IMP3 expression in prepubertal pure testicular teratomas.
abstract: Although the histologic appearance of pure testicular teratomas (PTTs) is similar in children and adults, the prognosis is dramatically different. Prepubertal PTTs are rare, with a benign clinical course, whereas the adult cases typically have malignant outcomes. Chromosome 12p abnormalities are seen in most adult testicular germ cell tumors but have not been found in prepubertal PTTs. IMP3 is an oncofetal protein that is highly expressed in many malignancies. Recently, we demonstrated IMP3 is expressed in adult mature testicular teratomas but not in mature ovarian teratomas. The aim of this study was to evaluate prepubertal PTTs for chromosome 12p abnormalities and expression of IMP3. A total of 11 cases (excision, n=1; orchiectomy, n=10) were obtained from the surgical pathology archives of 2 large medical centers (1957-2013). All 11 cases were investigated for isochromosome 12p and 12p copy number gain using interphase fluorescence in situ hybridization analysis and were examined by immunohistochemistry for IMP3 expression. Patients ranged in age from 0.9 to 7.0 (mean, 2.4) years. A positive immunohistochemical stain for IMP3 (cytoplasmic staining) was identified in 5 (46%) of 11 cases. Isochromosome 12p was detected in 2 cases (18%) that also expressed IMP3. Somatic copy number alterations of 12p were not observed (0%). We are the first to describe 12p abnormalities and IMP3 expression in prepubertal PTTs. Our data demonstrate a small subset of PTTs harbor typical molecular alterations observed in adult testicular germ cell tumors. Although prepubertal PTTs are considered to be benign neoplasms, it may be a heterogeneous group.
authors.affiliation: Department of Pathology, University of Massachusetts Medical Center, Worcester, MA 01655.
authors.forename: Kristine M
authors.initials: KM
authors.lastname: Cornejo
authors.affiliation: Department of Pathology, Indiana University School of Medicine, Indianapolis, IN 46202.
authors.forename: Liang
authors.initials: L
authors.lastname: Cheng
authors.affiliation: Department of Pathology, Boston Children's Hospital, Boston, MA 02115.
authors.forename: Alanna
authors.initials: A
authors.lastname: Church
authors.affiliation: Department of Pathology, Indiana University School of Medicine, Indianapolis, IN 46202.
authors.forename: Mingsheng
authors.initials: M
authors.lastname: Wang
authors.affiliation: Department of Pathology, University of Massachusetts Medical Center, Worcester, MA 01655. Electronic address: Zhong.Jiang@umassmemorial.org.
authors.forename: Zhong
authors.initials: Z
authors.lastname: Jiang
mesh_terms: D000367:Age Factors; D014408:Biomarkers, Tumor / Q000032:analysis* / Q000235:genetics*; D001706:Biopsy; D002648:Child; D002675:Child, Preschool; D002869:Chromosome Aberrations; D002881:Chromosomes, Human, Pair 12; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D007223:Infant; D008297:Male; D008404:Massachusetts; D009919:Orchiectomy; D016601:RNA-Binding Proteins / Q000032:analysis*; D046468:Sexual Development; D013724:Teratoma / Q000737:chemistry* / Q000235:genetics* / Q000473:pathology / Q000601:surgery; D013736:Testicular Neoplasms / Q000737:chemistry* / Q000235:genetics* / Q000473:pathology / Q000601:surgery
chemical_list: D014408:Biomarkers, Tumor; C498780:IGF2BP3 protein, human; D016601:RNA-Binding Proteins
keywords: 12p; FISH; Germ cell tumor; IMP3; Pediatric; Prepubertal; Teratoma; Testis