Metastatic Follicular Thyroid Carcinoma Masquerading as a Chordoma

Abstract

A 61-year-old Caucasian man presented with otalgia, dysarthria, and weight loss. Neurological examination revealed palatal hypomotility, and weakness of the facial and tongue muscles. Magnetic resonance imaging of the head demonstrated the presence of a soft tissue mass in the clivus. Histologic examination of resected tumor disclosed well-differentiated thyroid follicles that invaded the local osseous tissues. Physical examination and radioiodine images of the thyroid gland were normal. The serum thyroglobulin concentration was markedly elevated (1011 ng/mL). A 0.9-cm well-differentiated benign-appearing left thyroid lobe follicular neoplasm with a thick fibrous capsule was found following diagnostic thyroidectomy. This report illustrates that clinically significant distant metastases can arise from occult follicular thyroid neoplasms that, according to standard histologic criteria, are benign. The presence of a thick fibrous capsule, even in the absence of vascular or capsular invasion, may identify follicular neoplasms that have metastatic potential.

Skull Base Metastasis From Follicular Thyroid Carcinoma -Two Case Reports-

“…4,5,12,13,17,25,26,28,29,[32][33][34][35][36][37]41,42,45) Mean age was 55.6 years, ranging from 23 to 74 years. Bone metastasis from thyroid carcinoma is often observed in the sixth and seventh decades of life.…”

“…Bone destruction and local invasion to the surrounding soft tissues are common on radiological imaging, so that skull base metastasis from FTC is often mistaken as chordoma or chondrosarcoma. 4,33) The period between initial diagnosis and skull base metastasis from FTC ranged from 0 to 18 years, with a mean of 4 years. The possibility of skull base metastasis should be considered in the clinical course of FTC, and the patient should be meticulously followed up.…”

“…The lung is the most common metastatic site for thyroid carcinoma followed by the bone, 7,10,26,27) but skull metastasis of thyroid carcinoma is rare, with few reported cases. [1][2][3][4][5][6][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23]25,26,[28][29][30][31][32][33][34][35][36][37][38]40,41,44,45) The largest series of skull metastasis from thyroid carcinoma reported a frequency of only 2.5% among 473 patients. 26) Moreover, skull base metastasis from differentiated thyroid carcinoma is even rarer, with only 23 reported cases, including 17 cases of skull base metastasis from FTC that involved the clivus, cavernous sinus, sella turcica, petrous apex, and petrous ridge.…”

“…26) Moreover, skull base metastasis from differentiated thyroid carcinoma is even rarer, with only 23 reported cases, including 17 cases of skull base metastasis from FTC that involved the clivus, cavernous sinus, sella turcica, petrous apex, and petrous ridge. 4,5,12,13,17,25,26,28,29,[32][33][34][35][36][37]41,42,45) We treated two patients with skull base metastasis from FTC, and discuss the treatment modalities.…”

Solitary Metastasis From Occult Follicular Carcinoma of the Thyroid Mimicking Trigeminal Neurinoma. Case Report.

“…1) The metastatic pathways through which malignant tumors can involve the trigeminal nerve or ganglion can be divided into three groups: Subarachnoid dissemination, hematogenous dissemination from extracranial malignancy, and direct retrograde intracranial extension from nasopharyngeal tumors. The metastatic route in this case is considered to have been hematogenous.…”