title: Secondary malignant transformation of testicular teratomas: case series and literature review.
abstract: BACKGROUND
  Teratomas are a spectrum of neoplasms that can undergo malignant transformation. In the World Health Organization (WHO) classification of tumors, this entity was classified as «teratoma with somatic-type malignancy», was defined as a malignant neoplasm of non-germinal phenotype that originates in a teratoma.
  
  
  METHODS
  We present a serie of nine cases of testicular teratomas with secondary malignant transformation. From January 1995 to December 2011, we found a total of 306 cases of testicular tumors. Mixed germ cell tumors were the most frequently diagnosed malignancy with 45.7%.
  
  
  RESULTS
  Teratoma with secondary malignant transformation, represented 2.9% of all germinal tumors. Five cases originated within a mixed germ cell tumor, two cases from mature teratomas, and two from immature teratomas. The predominante malignant somatic component were sarcomas; two cases of chondrosarcoma, one rhabdomyosarcoma, and one case showing foci of chondrosarcoma and rhabdomyosarcoma. The case of osteosarcoma is notable for its rarity. Two cases showed epithelial malignancy in the form of an adenocarcinoma, and finally, two cases were primitive neuroectodermal tumors. At the time of diagnosis, five patients had metastases.
  
  
  CONCLUSIONS
  The transformation of germ cell tumors to somatic type malignancies is rare. The malignant component can originate from any of the three germ lines. These tumors are resistant to standard chemotherapy for a germ cell tumor and the clinical stage is the most important prognostic factor. At our institution, the malignant component that appeared most frequently was chondrosarcoma.
authors.affiliation: Servicio de Anatomía Patológica y Citopatología, Hospital Universitario Dr. José Eleuterio González, Universidad Autónoma de Nuevo León, Monterrey, Nuevo León, México.
authors.forename: L
authors.initials: L
authors.lastname: García-Labastida
authors.affiliation: Servicio de Anatomía Patológica y Citopatología, Hospital Universitario Dr. José Eleuterio González, Universidad Autónoma de Nuevo León, Monterrey, Nuevo León, México.
authors.forename: G S
authors.initials: GS
authors.lastname: Gómez-Macías
authors.affiliation: Servicio de Anatomía Patológica y Citopatología, Hospital Universitario Dr. José Eleuterio González, Universidad Autónoma de Nuevo León, Monterrey, Nuevo León, México.
authors.forename: J P
authors.initials: JP
authors.lastname: Flores-Gutiérrez
authors.affiliation: Servicio de Anatomía Patológica y Citopatología, Hospital Universitario Dr. José Eleuterio González, Universidad Autónoma de Nuevo León, Monterrey, Nuevo León, México.
authors.forename: M
authors.initials: M
authors.lastname: Ponce-Camacho
authors.affiliation: Servicio de Anatomía Patológica y Citopatología, Hospital Universitario Dr. José Eleuterio González, Universidad Autónoma de Nuevo León, Monterrey, Nuevo León, México.
authors.forename: J
authors.initials: J
authors.lastname: Ancer-Rodríguez
authors.affiliation: Servicio de Anatomía Patológica y Citopatología, Hospital Universitario Dr. José Eleuterio González, Universidad Autónoma de Nuevo León, Monterrey, Nuevo León, México.
authors.forename: O
authors.initials: O
authors.lastname: Barboza-Quintana
authors.affiliation: Servicio de Anatomía Patológica y Citopatología, Hospital Universitario Dr. José Eleuterio González, Universidad Autónoma de Nuevo León, Monterrey, Nuevo León, México. Electronic address: rgguajardo@yahoo.com.
authors.forename: R
authors.initials: R
authors.lastname: Garza-Guajardo
mesh_terms: D000293:Adolescent; D000328:Adult; D002471:Cell Transformation, Neoplastic; D006801:Humans; D008297:Male; D008875:Middle Aged; D009373:Neoplasms, Germ Cell and Embryonal / Q000473:pathology; D012189:Retrospective Studies; D013724:Teratoma / Q000473:pathology*; D013736:Testicular Neoplasms / Q000473:pathology*; D055815:Young Adult
keywords: Cancer; Cáncer; Malignant transformation; Teratoma; Testicle; Testículo; Transformación maligna