著明な発赤と特異な血管パターンを呈しadenoid cystic componentを伴ったbasaloid squamous cell carcinomaの1例

BSC with Characteristic Vascular Pattern by Magnifying Endoscopy, Report of a Case

要旨　症例は69歳の男性で，胸部食道にSMT様病変を認めた．頂部は陥凹を呈し，口側は発赤が強く拡大観察でループ状の不整血管を認めた（partA）．前壁側は中等度に発赤し拡大にて複数の無血管領域と同部を取り囲む異常血管を認めた（partB）．組織学的にpartAは深達度sm2のSCCで，表層にびらんを伴っていた．拡大観察でみられた血管は従来報告されていたsm癌の血管とは異なっており，びらんに伴う新生血管と思われた．partBでは，乏血性のBSC腫瘍塊，および腫瘍塊間の血管の露呈を認めた．拡大観察でみられた無血管領域とそれを取り囲む異常血管は，乏血性腫瘍塊と腫瘍塊間の血管と考えられ，BSCに特徴的な血管像と推察された．

　A 69-year-old male underwent esophagogastroscopy. A flat elevated lesion with central depression was observed on the middle esophagus. The color of the oral part was strongly red and magnifying endoscopy showed loop-shaped irregular vessels (part A). The color of the anterior part was moderately red and there were some depressed a-vascular areas with unusual surrounding vessels (part B).

　Histologically, regenerative vessels caused by erosion were observed on the surface of part A and SCC had invaded to the sm2. The vessels of part A observed with magnifying endoscopy were different from those of the part where SCC had invaded the submucosa. So, the loop-shaped vessels were considered to be regenerative vessels.

　Microscopic findings of part B revealed the exposure of BSC nests with few vessels and there were large vessels between the BSC nests. A-vascular areas of part B observed with magnifying endoscopy corresponded to the BSC nests and the unusual vessels surrounding a-vascular areas corresponded to the vessels between the BSC nests. Therefore, these findings with magnifying endoscopy were considered as the characteristic findings of BSC.