Ovary tumor
Germ cell tumors
Struma ovarii

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

Revised: 4 October 2018, last major update December 2012

Copyright: (c) 2002-2018, PathologyOutlines.com, Inc.

PubMed search: Ovarian struma ovarii
Cite this page: Ehdaivand, S. Struma ovarii. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/ovarytumorstruma.html. Accessed October 21st, 2018.
Definition / general
  • Rare monodermal teratoma composed predominantly of mature thyroid tissue
  • May show pathologic changes of thyroid gland including hyperfunctioning; malignancies are usually papillary thyroid carcinoma
  • Associated with mucinous cystadenoma, Brenner tumor, carcinoid tumor and dermoid cyst
Case reports
Gross description
  • Resembles red-brown thyroid tissue but usually multilocular cystic; usually unilateral
Gross images

Images hosted on PathOut server:

Contributed by Kseniya Korchagina, M.D.

Hyperfunctioning

Solid and cystic

Reddish brown solid mass

Cystic tumor



Images hosted on other servers:

Partially cystic tumor resembling thyroid

Microscopic (histologic) description
  • Thyroid follicles with colloid; other teratomatous elements may be present
  • Rarely has solid or pseudotubular patterns, microfollicles, abundant eosinophilic cytoplasm, abundant clear cytoplasm or minimal thyroid follicles
Microscopic (histologic) images

Images hosted on PathOut server:

Contributed by Kseniya Korchagina, M.D.:


Papillary thyroid carcinoma in struma ovarii



Other contributors:

Macrofollicular, microfollicular and solid areas

Solid tubular pattern

Oxyphilic cells arranged in nests

With peripheral formation of lutein cells


Resembling clear cell carcinoma

Cystic tumor

Thyroglobulin

With papillary carcinoma



Images hosted on other servers:

Thyroid-like follicles

Positive stains
  • Thyroglobulin
Molecular / cytogenetics description
Differential diagnosis
  • Metastatic thyroid carcinoma to ovary
Board review question #1
Which antibody is most useful for diagnosing struma ovarii?

A. PAX8
B. Thyroglobulin
C. Calcitonin
D. GATA-3
E. CEA
Board review answer #1
B. Thyroglobulin
Thyroid follicular cells are positive for thyroglobulin, TTF1 and PAX8. However, ovarian epithelium also shows immunopositivity for PAX8. Therefore, thyroglobulin and TTF1 antibodies are useful for the diagnosis of struma ovarii.