Papillary thyroid carcinoma arising from mature cystic teratoma ovary: a case report

Abstract

Introduction: Mature cystic teratoma is a kind of ovarian germ cell tumour. Malignant transformation in it is uncommon with thyroid cancer being rarely found. Given its rarity and nonspecific symptoms, misdiagnosis and indifference when compared to other ovarian lesions is very common.

Case presentation: Herein we report a case of a 58 year old post-menopausal female who presented with a history of abdominal distension and loss of appetite. She was found to have an abdominopelvic mass on examination and a raised CA125 levels for which she underwent an MRI pelvis which was suggestive of an O-RADS 5 lesion for which she underwent a staging laparotomy. The final histopathology and immunohistochemistry were suggestive of papillary thyroid carcinoma arising from a mature ovarian teratoma. After a multidisciplinary tumour board analysis, she was planned to be kept under follow–up with regular serum thyroglobulin monitoring. She has no signs of disease recurrence to date.

Discussion: Struma ovarii is one type of monodermal ovarian teratoma in which the tumour contains more than 50 % thyroid tissue. Diagnosis in such cases is difficult due to the lack of typical symptoms. In most of the cases, the diagnosis is incidental. Optimal treatment is still unclear given the rarity of the disease. In a few cases, thyroidectomy was done whereas in a few others it was omitted. Further therapy may include radioiodine treatment if needed.

Conclusion: To the best of our knowledge there is very scant information available on the natural history, prognosis and management of papillary thyroid carcinoma arising from mature cystic teratoma ovary. Hence, a multidisciplinary treatment approach may be needed for the same.