Endocrine Abstracts

Warthin-like variant of papillary thyroid carcinoma is a rare histologic variant of PTC; they resemble Warthin tumor of salivary gland, frequently associated with lymphocytic thyroiditis. There is scarce literature available regarding this tumor.

Clinical case: In August 2019 a 51-year-old female patient sought consult because she complained of constant pain in the anterior surface of the neck. Medical background: arterial hypertension, she had no history of family thyroid illnesses. On examination, she had a 2 cm painless nodule in the left thyroid lobe, with no lymph nodes. Ultrasonography: right lobe was measuring 45x20x21mm with multiple spongiform nodules, the largest: 16x9 mm; left lobe: 51x20x25 mm with a 19x17x17mm hypoechogenic nodule, with irregular margins, microcalcifications and minimal vascularization. In November 2019 ultrasound-guided FNA: nodule in right lobe: Bethesda II, nodule in left lobe: Bethesda VI: scattered cells and groups of cells with nuclear overlapping, elongated cells, anisokaryosis, 1-2 prominent nucleoli, intranuclear cytoplasmatic inclusions. There were two probable diagnoses: medullary thyroid carcinoma vs. an infrequent variant of papillary carcinoma. Hormonal laboratory: normal TSH, FT4 and calcitotin, negative TPO and antithyroglobulin antibodies. In January 2020 a total thyroidectomy and lymph nodes removal of region VI was performed. Pathology report: unifocal Warthin-like variant of papillary carcinoma of 0.7x0.7 cm, without lymphatic emboli, perineural and extra-thyroid invasion, lymphocytic thyroiditis in the remaining tissue. Region VI lymph nodes: 1/7 positive micro-metastasis of papillary carcinoma (<2 mm) without capsular invasion. Intermediate risk of recurrence, TNM: T1b, N1a, Mx. Under levothyroxine treatment: TSH 0.15 mUI/ml, thyroglobulin (TG) 0.04 ug/dl and negative antithyroglobulin antibody. Because of COVID-19 pandemic, treatment with 100 mCi radioiodine could be performed in October 2020 under recombinant TSH; whole body scan (WBS): positive in thyroid lodge and in the right region of the neck. Six months later, a neck ultrasonography showed a 11 mm adenopathy with cortical irregularity in III cervical region; a FNA was negative for neoplastic cells and thyroglobulin measurement in the needle washout after FNA was <0.1 ug/dl. In more than 3 years of follow-up, the patient had negative WBS, cervical ultrasonography and normal levels of thyroglobulin.

Conclusion: We presented a patient with a rare variant of papillary thyroid carcinoma associated with Hashimoto’s thyroiditis with negative serum thyroid antibodies. The patient had excellent response to the treatments in more than 3 years of follow-up. We need a longer follow-up to define the real risk of this type of thyroid cancer.