A case of synchronous isolated thyroid metastasis from a primary lung cancer presenting as thyroid primary: Diagnostic challenge

The thyroid metastasis from any primary is rare, and usually is a late event and presents as a thyroid swelling. Further, the diagnosis of a metastatic lesion in a patient with no antecedent history of any malignancy can be very challenging. Recently, a patient presented to us with a history of diagnostic evaluation suggesting a primary thyroid malignancy with a synchronous lung primary. After surgery for the thyroid swelling, final histopathology revealed a metastatic lesion from a lung primary. Here, we discuss this rare case of isolated synchronous thyroid metastasis from a lung primary and review the relevant literature.