Primary thyroid paraganglioma mimicking medullary thyroid carcinoma: A case report

Abstract

Abstract. Primary thyroid paraganglioma (TP) is an uncommon tumor, and in rare cases, this disease tends to mimic medullary thyroid carcinoma (MTC). The present study reports a rare case of primary TP mimicking thyroid carcinoma, accompanied by hyperthyroidism. A 30-year-old female presented with an anterior cervical mass. Pre-operative radiological studies and operative frozen section analysis indicated an atypical MTC. Primary TP was finally diagnosed by pathology and immunohistochemical staining. Laboratory examinations (thyroid hormones tests) and Tc99m emission computed tomography revealed hyperthyroidism. Gene analysis of TP-associated gene mutations was negative. Surgical resection was performed as a curative approach and there is currently no metastasis after 36 months of follow-up. Surgeons must be aware of this disease in order to ensure a correct diagnosis and to prevent them from performing unnecessary procedures. The current study presents a case of primary TP mimicking MTC, discusses the radiographic results and histological characteristics, and provides a review of the associated literature.

SDHB mutated paraganglioma imitating thyroid tumor: A case report and review of literature

“…Tumor appears as a solid hypoechogenic nodule on ultrasound sonography and as a low-density mass on CT scans. [2,15] In our case, PG was closely located to thyroid gland. Microscopically, distance between thyroid tissue and the tumor was only 0.45 mm.…”

“…[1] Most of tumors are asymptomatic and may be detected as palpable, painless mass of neck. [1,2] Less than 1% of head and neck PGs are functional with catecholamine production. A slight female predominance is noticed.…”

“…Mostly, these tumors arise in 5th-6th decade, but earlier presence is more frequently associated with hereditary syndromes. [1][2][3] The preoperative diagnosis of neck PGs may be difficult because of its non-specific radiological appearance and low hormonal activity. Fine needle aspiration is mostly nondiagnostic.…”

“…Fine needle aspiration is mostly nondiagnostic. [2][3][4] The precise frozen section diagnosis may be complicated because the morphology of the tumor is often disorganized and histological features like sustentacular cells are often unrecognizable. Therefore, these tumors tend to be misdiagnosed intraoperatively.…”

“…[3,6] Paragangliomas can be misdiagnosed with the others neuroendocrine-morphology resembling tumors like medullary thyroid carcinoma. [2,5] When diagnosis of paraganglioma is established, a testing for hereditary syndromes must be considered, because paragangliomas and pheochromocytomas (PG/PHEO) are among the most highly hereditary of all neoplasm. At least one third of these tumors are associated with proved germline mutations.…”