Secondary or second primary malignancy in the thyroid? metastatic tumors suggested clinically: a differential diagnostic task.

Objective: To describe the algorithms employed to explore the suggestion or consideration of metastatic malignancy in the thyroid.

Study Design: Thirty-seven cases with a history of malignancy (n = 21) and/or uncommon fine-needle aspiration biopsy (FNAB) findings (n = 37) were reviewed and reclassified according to The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC).

Results: The group was heterogeneous in terms of the final histopathology results: the suggested metastasis was confirmed in only half of the cases (11/21; 52.