Endocrine Abstracts

Introduction: Patients with Graves’ disease (GD) and thyroid nodules have an elevated risk of developing papillary thyroid carcinoma (PTC). Distant metastasis observed in 1-9% of patients with PTC. The classical subtype usually demonstrates favorable prognosis compared to other more aggressive PTC subtypes, for which an increased risk of extranodal metastases is observed.

Aim of the Study: We present an unusual case of a young male diagnosed with classical subtype PTC and Graves’ disease, metastasized to the lungs, at the time of diagnosis.

Case Presentation: A 36-year-old male patient presented with suppressed TSH levels (TSH=0, 01 mIU/l) and multinodular goiter in thyroid ultrasound. Laboratory tests showed elevated T3=2, 19 nmol/l, FT4=20, 1 pmol/l and TSI=114 IU/l (nv: <1, 0 IU/l). Thus, diagnosis of GD was established. Thyroid ultrasound revealed two large hypoechoic nodules, 1 mm and 1 mm respectively, with micro-calcifications (TIRADS 5), and suspicious deep cervical lymph nodes at compartment II. Fine needle aspiration biopsy for both nodules and lymph nodes with cytological findings were consistent with malignancy. Patient underwent total thyroidectomy with central and left lateral compartment lymph node dissection. The histological examination revealed multifocal PTC of classical subtype without thyroid capsule invasion and metastatic infiltration of lymph nodes (7/33), (pT2N1bMxR0). Subsequently, he received 120 mCi RAI. In the whole-body scan multiple foci of abnormal uptake concentration in lung parenchyma were observed. We performed a chest computed tomography confirming multiple nodular lesions, highly suggestive for metastatic infiltration. Noteworthy, as an incidental finding a solid renal mass 5, 4 cm in the upper pole of the right kidney, suspicious for malignancy, was noticed. Subsequently, patient underwent partial right nephrectomy and histological examination revealed a clear cell renal carcinoma Grade 2 (ISUP/ WHO 2022). Six months later, an additional RAI ablation treatment with 160 mCi, for the PTC derived lung metastases, was performed. Due to the unusual presentation of distant metastases from a classical subtype PTC and the presence of a second primary malignancy, genetic testing was performed for VHL and BRAF V600E/K gene mutation with no pathologic findings.

Conclusions: These findings suggest that prompt and meticulous evaluation of nodules in any patient with GD associated with nodular alterations must be considered. Autoimmunity seems to play a crucial role in tumor behavior since distant metastases from a PTC of classical subtype is an unusual finding.