X線診断の立場からみた直腸粘膜脱症候群

Diagnostic Radiological View on Mucosal Prolapse Syndrome of the Rectum

要旨　直腸粘膜脱症候群（mucosal prolapse syndrome；MPS）は比較的最近になって認識されるようになった疾患である．本症候群は炎症性病変でありながら大腸の種々の腫瘍性病変と類似した形態を呈する傾向がある．ときに進行大腸癌と誤診され，誤った治療が行われることがあるので，注意を要する．これまで11例のMPSを経験した，本病変は隆起を主体とする型と，潰瘍を主体とする型とに大別される．しかし，通常は病変に多彩性，多発性がみられる．次に形態的に経過を追えた4例から，①病変は可逆的であること，②短期間で形態が変わることがある，という知見を得た．診断に際しては，臨床症状，X線像，内視鏡像および生検組織診断との比較検討を行い，総合的に診断することが重要である．形態的な特徴像，年余にわたる経過例から得られた知見を，主にX線診断の立場から述べた．

　Mucosal prolase syndrome of the rectum is a disease entity which has been recently recognized. Although inflammatory in nature, it has a tendency to present with structural changes similar to a variety of neoplastic diseases of the colon. It tends to be mis-diagnosed as, in particular, advanced cancer of the colon leading to inadequate treatment.

　We have experienced 11 cases of mucosal prolapse syndrome of the rectum. They are classified into 2 types: mostly elevated and mostly ulcerative. Lesions can, however, have both diversity in appearance and multiplicity in origin. Follow-up observation of structural changes in 4 cases revealed the following facts: (1) lesions are reversible, and (2) structural changes can occur in a brief period of time. It is essential in diagnosing this syndrome that symptoms, radiological findings, and endoscopic findings with biopsy results are all integrated.

　Discussion was made from the standpoint of radiological diagnosis based on structural characteristics and follow-up findings for years.