UNLABELLED: Rectally localized colitis cystica profunda can simulate mucosecretory carcinoma. PURPOSE AND METHODS: Because endoscopic examination and barium enema do not clarify the diagnosis, other diagnostic imaging methods such as transrectal ultrasonography, computerized tomography, or magnetic resonance imaging are needed. RESULTS: Transrectal ultrasonography identifies multiple cysts in the rectal submucosa, with areas of echorefringent fibrosis between cysts, and confirms the absence of lymph node involvement or invasion of the muscular layer. Findings with computerized tomography and magnetic resonance imaging have not previously been described for colitis cystica profunda. With computerized tomography, the lesion appears as a noninfiltrating entity in the submucosa, with loss of perirectal layers of fatty tissue and thickening of the levator ani muscle. With nuclear magnetic imaging, nodulations produce intense signals that increase in T2, illustrating the mucoprotein content of the cysts. The presence in surgical biopsy material of large, whole cysts confirms the diagnosis. CONCLUSION: Reeducation of bowel habits aimed at avoiding straining and a high-fiber diet together with bulk laxatives can lead to complete remission of lesions in 6 to 18 months.
UNLABELLED: Rectally localized colitis cystica profunda can simulate mucosecretory carcinoma. PURPOSE AND METHODS: Because endoscopic examination and barium enema do not clarify the diagnosis, other diagnostic imaging methods such as transrectal ultrasonography, computerized tomography, or magnetic resonance imaging are needed. RESULTS: Transrectal ultrasonography identifies multiple cysts in the rectal submucosa, with areas of echorefringent fibrosis between cysts, and confirms the absence of lymph node involvement or invasion of the muscular layer. Findings with computerized tomography and magnetic resonance imaging have not previously been described for colitis cystica profunda. With computerized tomography, the lesion appears as a noninfiltrating entity in the submucosa, with loss of perirectal layers of fatty tissue and thickening of the levator ani muscle. With nuclear magnetic imaging, nodulations produce intense signals that increase in T2, illustrating the mucoprotein content of the cysts. The presence in surgical biopsy material of large, whole cysts confirms the diagnosis. CONCLUSION: Reeducation of bowel habits aimed at avoiding straining and a high-fiber diet together with bulk laxatives can lead to complete remission of lesions in 6 to 18 months.