Immature ovarian teratoma
Citation, DOI & article data
Immature ovarian teratomas are uncommon ovarian germ cell tumors. They differ from mature ovarian teratomas (dermoid cysts) both histologically by the presence of immature tissue, and clinically by their more malignant behavior.
They are considerably less common than mature ovarian teratomas, representing less than 1% of ovarian teratomas 1. They also affect a younger age group, occurring most often in the first two decades of life (accounting for 10-20% malignant ovarian tumors in this age group).
Presentation may be with a palpable pelvic mass or less commonly with abdominal pain 2.
An immature cystic teratoma is characterized by the presence of immature or embryonic tissue, as well as the mature tissue elements seen in a mature teratoma. The proportion of immature neuroepithelium present correlates with the tumor grade (and hence prognosis) 5.
Macroscopically, immature teratomas are large, encapsulated masses which have a prominent solid component. As well as this, they may feature many of the components seen in a mature teratoma, such as hair, cartilage, bone and calcification.
- ipsilateral mature cystic teratoma: ~25% 1
- contralateral immature teratoma: ~10% 1
The imaging appearance is typical of a large, heterogeneous mass with a prominent solid component. However, the spectrum of appearances ranges from a predominantly cystic to a mostly solid mass. Immature teratomas tend to be larger than mature cystic teratomas at initial presentation.
Extension through the tumor capsule may be present.
Immature teratoma may metastasize to the peritoneum, liver or lung. Metastasis to the brain has also been reported 7.
Ultrasound appearance is of a complex adnexal mass although it is non-specific. Calcifications may be present.
The presence of a prominent solid component containing calcifications and small foci of fat is suggestive. Cystic components may contain serous, mucinous, or sebaceous (fatty) material. Hemorrhage may be present.
Treatment and prognosis
Treatment is generally with oophorectomy, and if distant metastases are present, postoperative chemotherapy. Chemotherapeutic retroconversion is a phenomenon where the teratoma or its metastasis post-radiotherapy become more histologically mature than the primary lesion.
Prognosis depends on the stage.
- peritoneal rupture
On imaging consider:
mature ovarian teratoma
- tend to be smaller with more cystic change
- no evidence of metastases
- 1. Outwater EK, Siegelman ES, Hunt JL. Ovarian teratomas: tumor types and imaging characteristics. Radiographics. 21 (2): 475-90. Radiographics (full text) - Pubmed citation
- 2. Saba L, Guerriero S, Sulcis R et-al. Mature and immature ovarian teratomas: CT, US and MR imaging characteristics. Eur J Radiol. 2009;72 (3): 454-63. doi:10.1016/j.ejrad.2008.07.044 - Pubmed citation
- 3. Norris HJ, Zirkin HJ, Benson WL. Immature (malignant) teratoma of the ovary: a clinical and pathologic study of 58 cases. Cancer. 1976;37 (5): 2359-72. - Pubmed citation
- 4. Einarsson JI, Edwards CL, Zurawin RK. Immature ovarian teratoma in an adolescent: a case report and review of the literature. J Pediatr Adolesc Gynecol. 2004;17 (3): 187-9. doi:10.1016/j.jpag.2004.03.039 - Pubmed citation
- 5. Kumar V, Abbas AK, Fausto N. Robbins and Cotran pathologic basis of disease. W B Saunders Co. (2005) ISBN:0721601871. Read it at Google Books - Find it at Amazon
- 6. Hayat MA. Cancer Imaging, Instrumentation and Applications. Academic Press. (2007) ISBN:0123741831. Read it at Google Books - Find it at Amazon
- 7. Kurata A, Hirano K, Nagane M et-al. Immature teratoma of the ovary with distant metastases: favorable prognosis and insights into chemotherapeutic retroconversion. Int. J. Gynecol. Pathol. 2010;29 (5): 438-44. doi:10.1097/PGP.0b013e3181cef16b - Pubmed citation
- 8. Amsalem H, Nadjari M, Prus D et-al. Growing teratoma syndrome vs chemotherapeutic retroconversion: case report and review of the literature. Gynecol. Oncol. 2004;92 (1): 357-60. Gynecol. Oncol. (link) - Pubmed citation
- 9. Park SB, Kim JK, Kim KR et-al. Imaging findings of complications and unusual manifestations of ovarian teratomas. Radiographics. 28 (4): 969-83. doi:10.1148/rg.284075069 - Pubmed citation