Struma Ovarii : Differential Diagnosis

Comments:
Differential Diagnosis of Struma Ovarii: The clear/oxyphilic cells of struma ovarii can mimic morphology of clear cell ovarian carcinoma, Sertoli cell tumor, and steroid cell tumor. Features favoring struma ovarii include follicular architecture (which is readily recognizable in most cases) and intrafollicular colloid. An immunohistochemical panel of thyroglobulin, TTF-1, CK7, EMA, inhibin, and calretinin can help confirm the diagnosis. The thyroid tissue is immunoreactive for thyroglobulin, TTF-1, and PAX8. When struma ovarii is extensively cystic, it should be differentiated from serous or mucinous cystadenomas.

The image shows irrregularly-shaped thyroid follicles surrounded by copious collagenized stroma in a cyst wall from a case of struma ovarii.