体外式超音波が発見契機となったスキルス胃癌の1例

Sonographic Diagnosis of Diffusely Infiltrative Gastric Carcinoma, Report of a Case

要旨　症例は63歳，女性．上腹部痛と食思不振を主訴に受診した．体外式超音波では，胃体下部から前庭部にかけて不明瞭ながらも層構造の温存された壁肥厚が描出され，内腔の狭小化と壁硬化を伴っていた．胃X線および内視鏡検査では体下部から前庭部に粘膜の粗糙な壁硬化を認めた．びらん面からの生検により低分化型腺癌と診断され，幽門側胃切除が施行された．病理組織学的には胃壁全層に結合織の増生を伴うsignet cell carcinomaの浸潤がみられたが，超音波像は壁層構造の変化をよく反映していた．びまん性胃壁肥厚を呈する疾患は腫瘍性，炎症性とも多岐にわたるが，体外式超音波はそのスクリーニングおよび鑑別診断に有用であると思われた．

　A 63-year old woman was admitted to our hospital complaining of epigastralgia and anorexia. Physical examination revealed no remarkable abnormality. Most of her laboratory data were within normal limits except for slightly low albumin level. Extracorporeal ultrasound showed diffuse gastric wall thickening mainly of the distal stomach, with loss of compressibility and compliance. Wall stratification was demonstrable although the thickness of each layer was irregular and the margins between layers were blurred. The definitive diagnosis, by endoscopic examination including biopsy, was decided as poorly differentiated adenocarcinoma. The sonographic feature of the lesion represented the rough histopathological change findings of the resected specimen. Although there are many diseases presenting diffuse gastric wall thickening mimicking diffusely infiltrative gastric carcinoma, the assessment of sonographic features such as wall layer structure, echogenicity, and compressibility helps us differentiate each disease.