Thyroid paraganglioma: a case series of a rare head and neck tumor

Thyroid paragangliomas are rare neuroendocrine tumors. We present two cases analyzing their clinical presentation and pathology findings. A 44-year-old woman presented with a 33 mm left thyroid lobe mass. A 27-year-old male presented with a 27-mm right thyroid lobe mass and a FNA biopsy suggesting a follicular thyroid tumor. Both patients underwent total thyroidectomy. Vigorous bleeding was noted on the first case. Histologic sections revealed encapsulated tumors, whereas immunochemical stains were positive for chromogranin A, synaptophysin and NSE and negative for thyroglobulin, calcitonin, CEA and S-100. After an 18- and 12-month follow-up, respectively, both patients have no signs of local recurrence or distant metastasis. Preoperative diagnosis of thyroid paragangliomas was never attained in this series. Immunohistochemistry is mandatory for proper differential diagnosis. For the surgeon, the operation is technically demanding mainly due to the increased vascularity and friability of the tumor.