Struma Ovarii with Papillary Thyroid Carcinoma and Metastasis to the Appendix: A Case Report and Literature Review

Abstract

Struma ovarii is an infrequent type of teratoma arising from the ovary accounting for only 2% of all ovarian teratomas. These tumors have a benign biology with rare malignant transformation in about 3% of cases. The most common malignant transformation that arises from struma ovarii is papillary thyroid carcinoma. These neoplasms act in the same way as those arising from the thyroid gland, but due to the rarity of their occurrence there is still a debate over therapeutic options. We present a case of a 41-year-old Ethiopian Para IX woman presented with abdominal swelling for four years, accompanied by dull pain, satiety, and weight loss. Her vital signs were normal, and her abdominal examination revealed a large abdominopelvic mass. Her CA-125 was elevated, and her blood count, organ function tests, and serum electrolyte levels were normal. Abdominal ultrasound revealed a complex abdominopelvic mass with cystic and solid components, possibly ovarian teratoma. The patient underwent surgery, revealing a 14 by 10 cm right ovarian mass and a 3×3 cm appendiceal mass. Subsequently, total abdominal hysterectomy, bilateral salpingo-oophorectomy, total omentectomy, and appendectomy was done. Histopathologic evaluation revealed follicular proliferation of enlarged cells, with no papillary growth pattern. The case was diagnosed as malignant struma ovarii, a follicular variant of papillary thyroid carcinoma (FVPTC) with secondary deposits on the appendix. A complete thyroidectomy was done after the histopathology diagnosis. Malignant struma ovarii is rare making it challenging to treat since there are no established prognosticating histopathologic or clinical characteristics. The tumor size and metastasis determine the surgical treatment scope. Large-scale investigations are essential for prognostication and treatment options considering pathologic traits.

Keywords:

• struma ovarii
• papillary carcinoma
• malignant
• appendix
• metastasis
• teratoma

Abbreviation

FVPTC, follicular variant of papillary thyroid carcinoma; IHC, immunohistochemistry; MSO, malignant struma ovarii; PTC, papillary thyroid carcinoma.

Data Sharing Statement

The authors of this manuscript are willing to provide information regarding the case report. All the data can be provided by the corresponding author.

Ethical Clearance

After being reviewed by an ethics board, this case report was found to be morally sound.

Consent

The patient’s written informed consent to have the case details and accompanying images published was obtained before this manuscript was prepared. The chief editor of this journal can have access to a copy of the written consent.

Author Contributions

All authors made a significant contribution to the work reported, whether that is in the conception, study design, execution, acquisition of data, analysis and interpretation, or in all these areas; took part in drafting, revising or critically reviewing the article; gave final approval of the version to be published; have agreed on the journal to which the article has been submitted; and agree to be accountable for all aspects of the work.

Disclosure

The authors report no conflicts of interest in this work.

Additional information

Funding

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