0-Ⅱc型粘膜癌より発育進展したと考えられた表在食道類基底細胞癌の1例

Superficial Basaloid-Squamous Carcinoma of the Esophagus, Report of a Case

要旨　患者は83歳，女性．上部消化管検査にて，切歯より33～35cm左前壁に18×8mm大の中心に浅い陥凹を伴う隆起性病変（0-Ⅰpl＋Ⅱc）を認めた．Lt領域0-Ⅰpl＋Ⅱc NOMOPlO Stage Ⅰ，術前組織診断は扁平上皮癌であった表在食道癌に対してEMRを施行した．病理組織学的診断はbasaloid-squamous carcinoma，0-Ⅰpl＋Ⅱc，sm₂，ly(－)，v(－)，深部断端(－)．0-Ⅱc病変部は0-Ⅰpl病変の頂部に存在する小さな扁平上皮癌であったが，0-Ⅰpl病変である上皮下に広く浸潤する類基底細胞癌との連続性を認めた．本症例は0-Ⅱc病変より発育した0-Ⅰpl病変と考えられ，扁平上皮癌が類基底細胞癌様に分化していく発育進展様式を示唆する症例と思われた．

　We reported the case of an 83-year-old woman with basaloid-Squamous carcinoma (BSC) of the esophagus. In our patient, upper GI x-ray examination showed a small protruding lesion in the distal esophagus. Endoscopic examination revealed a protruding tumor with a small slightly depressed area at the center of protrusion. It was approximately 18 mm in size at 33 cm from the incisors. A bite biopsy suggested that it was a moderately differentiated squamous cell carinoma. And endoscopic mucosal resection was indicated because of the age and poor general condition of the patient. Histologically, the protruding-type lesion was a BSC with moderate invasion into the submucosa. The 0-Ⅱc lesion consisted of moderately differentiated squamous cell carcinoma. There was histological continuity between BSC in the submucosa and SCC in the epithelial layer (Fig.3 d). These facts strongly suggested that BSC in the submucosa had originated from an overlying 0-Ⅱc type SCC.