PURPOSE: To determine the value of endoscopic ultrasound (US) in the diagnosis of mucosal prolapse syndrome (MPS), also known as solitary ulcer of the rectum. MATERIALS AND METHODS: Three male and two female patients (age range, 17-66 years) with biopsy-proved MPS underwent endoscopic US. The average rectal wall thicknesses of the affected areas were compared with those of normal-appearing mucosa. RESULTS: The gross appearance of the rectal lesions was classified into three types: polypoid (n = 2), flat (n = 1), and ulcerative (n = 2). In all three types of lesions, endoscopic US demonstrated smooth, diffuse thickening of the third layer of the rectal wall; the other layers had minimal thickening. Neither a solid hypoechoic mass nor a transmural infiltrating lesion was visible, and the five-layer structure of the rectal wall was completely preserved. In the polypoid lesions, the third layer was winding as well as thickened, and microcystic components were occasionally found. CONCLUSION: Endoscopic US enabled differentiation of MPS from other conditions such as malignant neoplasia and Crohn disease.
PURPOSE: To determine the value of endoscopic ultrasound (US) in the diagnosis of mucosal prolapse syndrome (MPS), also known as solitary ulcer of the rectum. MATERIALS AND METHODS: Three male and two female patients (age range, 17-66 years) with biopsy-proved MPS underwent endoscopic US. The average rectal wall thicknesses of the affected areas were compared with those of normal-appearing mucosa. RESULTS: The gross appearance of the rectal lesions was classified into three types: polypoid (n = 2), flat (n = 1), and ulcerative (n = 2). In all three types of lesions, endoscopic US demonstrated smooth, diffuse thickening of the third layer of the rectal wall; the other layers had minimal thickening. Neither a solid hypoechoic mass nor a transmural infiltrating lesion was visible, and the five-layer structure of the rectal wall was completely preserved. In the polypoid lesions, the third layer was winding as well as thickened, and microcystic components were occasionally found. CONCLUSION: Endoscopic US enabled differentiation of MPS from other conditions such as malignant neoplasia and Crohn disease.