雪本 幸美¹, 大西 さゆり¹, 中村 雅美¹, 河崎 正², 横沢 保³, 宮内 昭³

Yukimi YUKIMOTO¹, Sayuri OONISHI¹, Masami NAKAMURA¹, Tadashi KAWASAKI², Tamotsu YOKOZAWA³, Akira MIYAUCHI³

¹河崎内科病院超音波検査室, ²河崎内科病院内科, ³隈病院外科

¹Department of Ultrasonographic Laboratory, Kawasaki Naika Hospital, ²Department of Internal Medicine, Kawasaki Naika Hospital, ³Department of Surgery, Kuma Hospital

キーワード : calcitonin, medullary thyroid carcinoma, RET proto-oncogene

A 50-year-old woman with severe headache and vertigo was admitted on an emergency basis in May 1994. Physical examination showed marked hypertension, laterality of pulse in the bilateral upper extremities, and a vascular systolic murmur was detected to auscultation in the supraclavicular region. Intra-arterial digital subtraction angiography of the cervix showed moderate stenotic lesions in the left common carotic artery and the left subclavian artery. These findings supported a diagnosis of Takayasu areteritis. Several hypoechoic lesions were discovered in the bilateral lobes of the thyroid gland on ultrasound examination and were carefully monitored thereafter. Follow-up examination 5 years later showed an increase in the size of the hypoechoic mass in the left lobe. Ultrasonographically guided aspiration biopsy revealed papillary carcinoma in the right lobe and medullary carcinoma in the left lobe. Total thyroidectomy with a left modified radical neck dissection was carried out. The extracted specimens showed a yellow-white medullary thyroid carcinoma about 10 mm in diameter in the left lobe, and several papillary microcarcinomas in the right lobe. The medullary thyroid carcinoma was diagnosed as a sporadic type when careful examination failed to detect RET proto-oncogene, pheochromocytoma or hyperparathyroidism.　We conclude that particular consideration should be given to the possibility of medullary carcinoma when an oval, homogenous, hypoechoic lesion 10 mm or smaller in diameter with calcification is observed in the thyroid gland on ultrasound examination.