Category: Thyroid

Monitor: 3

3 - AN ATYPICAL FOLLICULAR ADENOMA OF STRUMA OVARII ARISING FROM A CLASSIC VARIANT PAPILLARY THYROID CARCINOMA

Friday, Apr 26
11:30 AM – 12:00 PM

Objective :

PTC is the most common thyroid cancer and rarely associated with metastasis. Most common sites of metastasis are lungs and bones. Only a few cases of ovarian metastasis have been described in literature. We report a rare case suggestive of an atypical follicular adenoma of struma ovarii arising from a classic variant PTC.


Methods :

This is the case of a 40 years old woman with T2DM, mixed hyperlipidemia, PTC classic variant involving isthmus s/p total thyroidectomy without initial RAI referred for disease monitoring. No family history of thyroid illness or radiation exposure. Unremarkable PE with normal vital signs, weight of 194lbs, BMI 34.37kg/m2.


Results : Patient had a benign clinical course until increasing thyroglobulin levels were encountered during f/up with negative thyroid sonogram. She then received 59.7mCi I131 therapy. Scintigraphic evidence of a radioiodine avid lesion in the midline of the pelvic region was detected in WBS post ablation. Laparoscopic right oophorectomy and cystectomy was done. Phenotype study was compatible with follicular variant of PTC arising in an atypical follicular adenoma of struma ovarii measuring 1.2 cm. F/up PET CT showed no further hypermetabolic lesions.


Discussion : PTC is associated with good prognosis and low metastatic power. Presence of distant metastasis is an important prognostic factor since the 30 years mortality rates increase to 43% as a result of distant recurrence occuring decades after primary tumor. Our case presented with ovarian cancer two years after confirmation of PTC. Differential diagnosis should have to be considered between thyroid cancer arising from a struma ovarii and ovarian metastasis originating from PTC, since prognosis and clinical management are different. Thyroid carcinoma originating from struma ovarii is reported to occur much more commonly than an ovarian metastasis from thyroid.


Conclusion : In literature there are not enough studies to draw conclusions about prognosis and best clinical management of ovarian metastasis from thyroid cancer. 131I scan and serum thyroglobulin are widely employed during f/up of thyroid cancer and in the assessment of the best therapy to use after surgery. Even though ovarian involvement by a primary thyroid cancer is a rare event, it should be considered since it is a negative prognostic factor worsening oncological outcome.

Kyrmarie Davila

Endocrinology Fellowship at San Juan City Hospital Program
Endocrinology Fellow
Rincon, Puerto Rico

Endocrinology Fellow In Training

Kyrmarie Davila Torres

Michelle Mangual Garcia