Endocrine Abstracts

Background: Familial papillary or follicular thyroid carcinoma is a rare, nonmedullary thyroid carcinoma characterized by the presence of the disease in two or more first-degree relatives. With the worldwide increasing rate of papillary thyroid carcinoma (PTC) in the recent years, the familial form of the disease (FNMTC) has also become more common than previously reported, however remains less well described clinical entity. Here we report a case of PTC in identical twins.

Case presentation: The index case was a 41-year-old male who referred to our clinic in December 2021 with complaints of fatigue, shortness of breath, high blood pressure, weight gain. On physical examination he had normal vital signs except for tachycardia; The thyroid hormone report was standard and the neck ultrasound revealed presence of nonpalpable <1 cm hypoechoic solitary nodule with irregular margins, vertical orientation, highly vascularized, corresponding to TIRADS IV category. Then, FNAB was performed with the BETHESDA VI report. The patient underwent total thyroidectomy and bilateral neck dissection. Histopathological report of papillary microcarcinoma with microscopic extrathyroid extension, lymphangio and perineural invasion. The patient’s family members were worried, and we performed neck ultrasound in identical twin brother. He was also diagnosed with PTC. The patient underwent total thyroidectomy with bilateral neck dissection, and received radioactive iodine (100 mCi each) treatment.

Conclusion: Our case is important because it raises awareness of a rare disease and represents an interesting challenge for clinician. Many controversies are associated with the management of FNMTC. The decision to screen members of FNMTC kindreds with thyroid ultrasound is neither recommended nor discouraged but we strongly recommend that the first degree relatives should be considered for screening.