森本 由紀子¹, 平井 都始子¹, 伊藤 高広², 丸上 永晃¹, 山下 奈美子¹, 豊國 美鈴¹, 杉井 公美¹, 齊藤 弥穂¹, 大石 元³

Yukiko MORIMOTO¹, Toshiko HIRAI¹, Takahiro ITOH², Nagaaki MARUGAMI¹, Namiko YAMASHITA¹, Misuzu TOYOKUNI¹, Kumi SUGII¹, Miho SAITO¹, Hajime OHISHI³

¹奈良県立医科大学附属病院中央内視鏡・超音波部, ²奈良県立医科大学附属病院放射線科, ³奈良県健康づくりセンター

¹Department of Endoscopy and Ultrasound, Nara Medical University, ²Department of Radiology, Nara Medical University, ³Nara Health Promotion Center

キーワード : hypopharyngeal cancer, pyriform sinus, hypopharynx, ultrasound

超音波検査で観察できた2 cm以下の下咽頭癌2例を経験した．正常下咽頭超音波像と経験症例の超音波像について報告する．超音波では頸部正中やや外側の横断走査，ほぼ頸動脈分岐部レベルで，甲状軟骨後方に喉頭が描出され，隣接する喉頭蓋ヒダを隔てて，内腔に空気を有する梨状陥凹の前外側壁が観察できる．症例1，症例2ともに70歳代男性，内視鏡検査で左梨状陥凹に2 cm以下の腫瘍を指摘され，頸部リンパ節転移検索のため超音波検査を施行した．いずれの病変も超音波で左梨状陥凹内腔を占める低エコー腫瘤として描出され，カラードプラ法では喉頭蓋ヒダから腫瘤内部に流入する豊富なカラー表示が認められた．下咽頭癌は初発症状に乏しく，リンパ節転移を契機に進行癌で発見されることが多く，発生部位は梨状陥凹が60‐70％と最も多い．今回経験した2症例は梨状陥凹の2 cm以下の病変であったが超音波検査で明瞭に描出可能であった．頸部超音波検査の際に，特に高齢男性，アルコール多飲や喫煙歴を持つハイリスクの症例には，梨状陥凹の観察を心掛けることが，下咽頭癌の早期発見につながる可能性がある．

We encountered two patients with small hypopharyngeal cancer who could be evaluated in detail by ultrasonography. Ultrasound images of a normal hypopharynx and those of the two patients are described. On ultrasonography, the larynx is visualized posteriorly to the thyroid cartilage nearly at the level of the carotid artery bifurcation by transverse scanning. Being separated by the adjacent epiglottic fold, the anterolateral wall of the pyriform sinus conty, and underwent ultrasonography to search for cervical lymph node metastasis. Both lesions were visualized as a hypoechoic mass occupying the cavity of the left pyriform sinus and, on color Doppler ultrasonography, showed rich color signals flowing from the epiglottic fold into the maining air is observed. Both patients were males in their 70s, were found to have a tumor 2 cm or smaller in diameter in the pyriform sinus by endoscopass. Hypopharyngeal cancer is often detected at an advanced stage because of inconspicuous pharyngeal symptoms. It occurs most frequently (60-70%) in the pyriform sinus. In the two patients presented here, the lesions were 2 cm or less in diameter and were located in the pyriform sinus, but they could be clearly delineated on ultrasonography. In ultrasonography of the neck, examination of the pyriform sinus may lead to the early detection of hypopharyngeal cancer in high-risk patients such as elderly males, heavy drinkers, and those with a smoking history.