内臓逆位を伴った甲状腺癌の1例

A case of thyroid carcinoma with situs inversus totalis

はじめに

　内臓逆位は，胸腹部臓器の左右非対称性が鏡像となる先天性異常であり，3,000〜10,000人に1人の割合で認められる比較的まれな疾患である。今回，われわれは内臓逆位を伴う甲状腺乳頭癌患者に対して甲状腺全摘術を施行し，術前画像評価の重要性および術中における解剖学的特徴を経験した。本症例を通して，内臓逆位患者に対する甲状腺手術における注意点と，3D-CTによる術前評価の有用性について考察する。

　Situs inversus totalis is a rare congenital anomaly that can make it difficult to understand anatomical structures during surgery. An 81-year-old woman presented with swelling in the right neck. She had a history of complete visceral inversion. A neck CT scan revealed a 70 mm tumorous lesion with calcification in the right lobe of the thyroid gland. In this case, we performed a two-stage total thyroidectomy for papillary thyroid cancer. By thoroughly assessing the vascular structure using preoperative 3D-CT, we were able to predict the course of the recurrent laryngeal nerve as a mirror image of normal anatomy and perform a safe surgery. In thyroid surgery for patients with visceral inversion, preoperative imaging-based anatomical assessment is extremely important.