Thyroid Paraganglioma In A Patient With A History Of Carotid And Vagal Paraganglioma: Metastatic Or Primary Tumor?

Paragangliomas (PGs) are extremely rare multicentric neoplasms. Hereditary or familial PGs are associated with germline mutations in succinate dehydrogenase genes, seen in one-third of cases. Primary PGs of the thyroid are uncommon neuroendocrine neoplasms that account for 0.012% of all head and neck lesions. Although majority of these tumors are solitary, familial PGs are associated with synchronous tumors (carotid/vagal). We report an interesting case of primary thyroid PG in a patient with a previous history of a right carotid body, right vagal PGs and positive familial history, confining the differential diagnosis to recurrent lesions, which is the most common occurrence or new primary or a metastatic lesion. However, long interval and surgical anatomy suggests the diagnosis to be a primary lesion. In conclusion, although these lesions present multicentrically present at varying intervals, their occurrence at anatomically distinct sites should raise the concern for a new primary PG.