多発食道癌の病理―ルゴール不染帯多発との関連

Clinicopathological Study of Multicentric, Primary Esophageal Carcinomas－Correlation with Multiple Occurrence of Unstained Area by Lugol's Iodine

要旨　食道の単発癌と多発癌の臨床病理学的な異同を明らかにするために，術前未治療の食道原発扁平上皮癌の外科的切除材料を用いて癌の発生頻度，癌巣の大きさ，個数，壁深達度と背景粘膜におけるルゴール不染帯の出現頻度，各病理組織像，大きさ，個数について比較検討した．単発癌と多発癌の類似点としては男性に好発すること，癌巣の大きさは進行型が全例16mm以上であること，背景粘膜に出現するルゴール不染帯は大きさ3～5mmの萎縮上皮が最多であること，一方，相違点としては癌巣の大きさは単発の表在型癌では全例11mm以上であるが，多発の表在型癌では10mm以下のものが半数以上を占めていること，背景粘膜におけるルゴール不染帯の出現頻度は単発の表在型癌および多発癌に比べて単発の進行型癌が最も低いことが挙げられた．以上の解析結果から表在型癌の背景粘膜にはルゴール不染帯が出現しやすいこと，および多発の表在型癌の癌巣サイズは10mm以下のものが多いことが明らかになった．このような特徴を知ることはルゴール染色法を併用した内視鏡検査において多発癌，特に多発表在型癌の発見およびEMR後の異時性多発癌の早期発見において臨床的意義がある．

　Four hundred and ninety-six lesions of primary esophageal squamous cell carcinomas from 346 patients without preoperative treatment were studied histopathologically to analyze differences and similarities between unicentric and multicentric carcinomas. The esophageal carcinomas were collected from 1996 through 2000 and were classified as follows: 261 unicentric carcinomas and 85 multicentric carcinomas. We reached the following conclusions.

(1) The size of unicentric, superficial carcinomas was mainly over 10 mm. In contrast, the size of multicentric, superficial carcinomas was less than 10 mm in the majority of cases.

(2) The size of unstained areas by Lugol's iodine in the surrounding mucosa in both unicentic and mul-ticentric carcinomas was mainly less than 5 mm.

(3) Unstained areas by Lugol's iodine in the mucosa surrounding superficial carcinomas were of common occurrence.

(4) Recognition of size of unstained areas by Lugol's iodine is useful for detecting multicentric, superficial carcinomas and also for detecting metachronous, multicentric carcinomas after endoscopic mucosal resection.