0-Isep型を呈し著明なリンパ球浸潤を伴った食道低分化型扁平上皮癌の1例

Poorly Differentiated Squamous Cell Carcinoma of the Esophagus with Lymphoid Stroma Seeming to be Type 0-Isep, Report of a Case

要旨　患者は67歳，男性．上部腹部不快感を主訴に近医を受診した．上部消化管内視鏡検査で胸部下部食道左後壁に病変を指摘されたが，繰り返す生検の結果では明らかな悪性所見が得られず，精査加療目的で当院に紹介入院となった．内視鏡検査では，病変の表面全体がほぼ正常食道上皮に被覆され粘膜下腫瘍様の形態を呈した．中心に軽度の陥凹と少量の白苔付着を伴う隆起性病変を認め，ヨード染色で濃染した．当院での生検組織の一部で扁平上皮癌を認め0-lsep型表在癌，深達度SMと診断した．本人の希望により，内視鏡的粘膜切除術を先行した．病理組織学的検索の結果，上皮下発育を示した低分化型扁平上皮癌で，間質に著明なリンパ球浸潤と濾胞形成を伴っており，深達度pT1b（sm2），inf_γ，ly₀，V₀と診断された．リンパ節転移の可能性を否定できず，右開胸開腹胸部食道切除術D₃を追加施行した．その結果，リンパ節3，7番に癌の転移を認，pN₂，pStageⅡの診断となった．

　An esophageal lesion was detected in a 67-year-old man by endoscopy at a nearby hospital, when he visited there complaining of upper abdominal discomfort. No malignant features were noted in the biopsy specimen taken from the esophageal lesion on the left-posterior wall of the lower thoracic portion. He was admitted to the Tokai University hospital for further clinical examination and treatment. The endoscopic findings revealed that the lesion was protruding with a central slight depression, covered by non-epithelial esophageal epithelium, mimicking a submucosal tumor, and stained with iodine. The biopsy specimen showed atypical squamous cells. Under the diagnosis of type 0-Isep, superficial esophageal carcinoma, endoscoipc mucosal resection was performed at the patient's request. The histopathological findings of the resected specimen led to the diagnosis of poorly differentiated squamous cell carcinoma with marked lymphoid stroma and overlying non-epithelial squamoua epithelium. The depth of invasion was sm₂, inf_γ, ly₀, v₀. A subtotal esophagectomy using a right thoraco-laparotomy with lymph node dissection, D₃, was performed because of suspicion of lymph node metastasis. Metastasis of lymph nodes #3, 7 was positive for cancer cells.