Metastatic Papillary Thyroid Carcinoma Arising from Malignant Struma Ovarii: A Case Report

Abstract

Aim: To present an uncommon case of recurrent metastatic papillary thyroid carcinoma arising from malignant struma ovarii. As the occurrence of the tumour is uncommon due to its rarity, there has been lack of data in regards to treatments and follow-up procedures for this tumour. Background: Struma ovarii is a rare form of ovarian teratoma predominantly composed of thyroid tissue. Although typically benign, malignant transformation can occur, most commonly into papillary thyroid carcinoma. Due to its rarity, there is limited literature on its clinical behaviour, optimal treatment strategies, and follow-up protocols. By reporting this rare case, we may be able to contribute to improve medical understanding and guiding future treatment. Case Presentation: A case of 61 years old parity one lady presented with postmenopausal ovarian mass. She presented with abdominal distention with reduced effort tolerance. The patient underwent total abdominal hysterectomy bilateral saphingoophrectomy, appendicectomy, omentectomy and histopathology reported as papillary thyroid carcinoma arising from malignant struma ovarii. Total thyroidectomy was performed and results were negative for malignancy. The patient experienced recurrence of the disease on the pelvic 10 months post total abdominal hysterectomy bilateral salphingoophrectomy requiring debulking surgery and Hartmann’s procedure. Discussion: Struma ovarii is a rare benign teratoma originated from the ovary represent 2% of all ovarian teratoma. Malignant transformation occurs in about 3% of cases. The most common malignant type transformation of struma ovarii is papillary thyroid carcinoma with 5% rate of metastases. Diagnosis is made postoperatively by histological findings and up until now there is no standard guideline in managing this rare illness. Conclusion: Papillary thyroid carcinoma arising from malignant struma ovarii is an unusual presentation. Diagnosis and management of this entity is challenging and up until this moment there is no standardized treatment for this disease. Thus, intervention should be made individualized considering few factors such as the fertility concern, severity of the disease and histopathological diagnosis. Multidisciplinary discussion is recommended in establishing the diagnosis and management for the patient.