Ovary tumor
Germ cell tumors

Author: Shahrzad Ehdaivand, M.D. (see Authors page)

Revised: 22 June 2016, last major update December 2012

Copyright: (c) 2002-2016, PathologyOutlines.com, Inc.

PubMed Search: Ovary teratoma immature [title]

Related: Endodermal teratoma, Ependymoma, Growing teratoma syndrome
Cite this page: Teratoma-immature. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/ovarytumorteratomaimmature.html. Accessed October 22nd, 2016.
Definition / General
  • Malignant tumor, whose tissue resembles embryonal or fetal tissue
  • Usually prepubertal or young women (mean 18 years)
  • Most recurrences within 2 years; presence of yolk sac component is best predictor of recurrence in pediatric tumors (Am J Surg Pathol 1998;22:1115)
  • Common errors are classifying differentiating tissue as immature and not recognizing hepatoid and well-differentiated glandular patterns of yolk sac tumor
Case Reports
  • 17 year old girl with predominant malignant retinal anlage component, tumor parthenogenically derived, GFAP+ and neuroglia by EM (Am J Surg Pathol 1985;9:221)
  • Surgery, multiagent chemotherapy
  • Better prognosis if only mature teratoma found after chemotherapy, although abnormal karyotype is maintained in mature teratoma
Gross Description
  • Bulky, solid or cystic with necrosis, hemorrhage
Gross Images
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Capsular rupture


Mixture of solid
and cystic tissues

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Hepatic teratoma with yolk sac component

Micro Description
  • Usually neurogenic elements (GFAP+); mesodermal elements common; some tumors derived primarily of esophageal, liver and intestinal structures (endodermal)
  • Grading: histologic grade is based on proportion of tissue containing immature neuroepithelium
  • Norris grading system (correlates best with extraovarian spread, survival)
  • 1: abundant mature tissue, loose mesenchymal tissue with occasional mitoses, immature cartilage and tooth anlage
  • 2: less mature tissue than grade 1, rare foci of neuroepithelium with mitoses, < 4 low power fields in any one slide
  • 3: little / no mature tissue; numerous neuroepithelial elements merging with cellular stroma occupying 4+ low power fields
Micro Images
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Embryonal epithelium

Implant on peritoneum

Mitotic figures

Neuroectodermal tissue

Peritoneal gliomatosis

Six neuroepithelial

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Immature elements

Neural tissue