Malignant struma ovarii: surgical, histopathological and survival outcomes for thyroid-type carcinoma of struma ovarii with recommendations for standardising multi-modal management. A retrospective case series sharing the experience of a single institution over 10 years

Arch Gynecol Obstet. 2021 Apr;303(4):863-870. doi: 10.1007/s00404-021-05969-0. Epub 2021 Jan 29.

Abstract

Purpose: Struma ovarii is rare, accounting for 0.3-1% of ovarian tumours. Malignant transformation may occur, most often into papillary thyroid carcinoma. There is a paucity of data pertaining to malignant struma ovarii. This paper shares a decade of experience of a single institution in the management of this rare ovarian cancer, exploring the characteristics of this tumour and suggesting a standardised approach to treatment and follow-up.

Methods: All patients treated for malignant struma ovarii within a large cancer centre over one decade were identified and data collected retrospectively on presentation, diagnosis, management, follow-up and survival outcomes. A literature review was also undertaken.

Results: Eleven cases of malignant struma ovarii were managed in the Oxford Cancer Centre between 2010 and 2019, 6 of which were of papillary thyroid carcinoma sub-type. No cases were correctly diagnosed pre-operatively. All patients had stage I disease and were managed surgically-but with variation in radicality. Patients identified as high-risk based on final histopathology underwent additional thyroidectomy and radio-active iodine ablation therapy. One case of synchronous malignancy of the thyroid gland proper was identified. No disease recurrence occurred.

Conclusion: Malignant struma ovarii present a diagnostic challenge. Multi-disciplinary team (MDT) input is essential. Unilateral salpingo-oophrectomy may be adequate if stage I; reserving more radical surgery for advanced disease. Histopathological risk-stratification should be used to identify those most likely to benefit from adjuvant thyroid-targeting therapies. Patients require follow-up, anticipating an overall good prognosis.

Keywords: Histopathology; Ovarian cancer; Papillary thyroid carcinoma; Radio-active iodine ablation; Struma ovarii; Thyroidectomy.

Publication types

  • Review

MeSH terms

  • Adult
  • Aged
  • Combined Modality Therapy / methods*
  • Female
  • Humans
  • Middle Aged
  • Ovarian Neoplasms / mortality*
  • Ovarian Neoplasms / pathology*
  • Retrospective Studies
  • Struma Ovarii / mortality*
  • Struma Ovarii / pathology*
  • Survival Analysis
  • Time Factors