スキルス胃癌と鑑別を要する非腫瘍性疾患―胃梅毒

Differential Diagnosis between Gastric Syphilis and Scirrhous Carcinoma of the Stomach

要旨　胃梅毒は幽門前庭部に好発するが，画像上，幽門部のスキルス胃癌との鑑別が問題となることがある．スキルス胃癌との鑑別点としては，胃梅毒は，X線では狭窄は左右対称性の漏斗状を呈し，病変は幽門輪部にまで及び幽門輪の開大を伴いやすいこと，内視鏡では粘膜は易出血性でびらんや多発性の浅い不整形潰瘍を伴うが，壁の伸展不良は比較的軽度であることが挙げられる．さらに，梅毒性皮疹類似の特異的な胃粘膜疹が確認できれば鑑別は容易である．画像上，幽門前庭部のスキルス胃癌が疑われた場合には，鑑別診断として胃梅毒も念頭に置き，梅毒血清反応をチェックすべきである．

　Gastric syphilis, which has a predilection for involvement of the pyloric antrum, may resemble scirrhous carcinoma of the gastric antrum. The radiographic finding of gastric syphilis is characterized by a narrowed lumen of the entire antrum to the pylorus ring producing a funnel-shaped appearance. The endoscopic feature is multiple irregular and shallow erosions/ulcers with associated edema and hemorrhage in the antrum, the wall rigidity of which is not so severe. In addition, if multiple large verruciform lesions resembling syphilitic skin lesions are observed in the gastric body, they are valuable for the diagnosis of gastric syphilis.

　If the scirrhous carcinoma of the gastric antrum is suspected morphologically, bearing gastric syphilis in mind as one of the possible differential diagnoses, serologic tests should be carried out to test for syphilis.