Clinical Pitfalls in the Diagnosis and Treatment of Solitary Rectal Ulcer Syndrome / 대한소화기내시경학회지

ABSTRACT

BACKGROUND AND AIM: Solitary rectal ulcer syndrome (SRUS) is a rare disease, but it is encountered in the colorectal field. SRUS is usually associated with defecation disorders such as puborectalis dysfunction, rectal occult or overt prolapse, descending perineum syndrome, and so forth. Without knowledge about SRUS, the lesion could be easily overlooked or misdiagnosed. The histologic characteristics of SRUS are fibromuscular obliteration in the lamina propria and/or misplaced mucin-filled cysts below the muscularis mucosae, this latter condition being commonly referred to as colitis cystica profunda. However, these characteristics, even though they exist, are often missed in the initial biopsy specimens from SRUS patients, leading to misdiagnoses which cause delayed diag-nosis and treatment. In spite of the incomplete histologic indications, a careful and con-scientious clinician, using clinical features and characteristic endoscopic findings, would not misdiagnose SRUS lesions. In other words, the clinical features and endoscopic find-ings are as important as, if not more important than, the histologic findings in the diag-nosis of SURS lesions. METHODS: The authors reviewed and analyzed 18 recently experi-enced, biopsy-proven cases of SRUS with emphasis on gross classification and initial pathologic misdiagnoses. RESULTS: The most common age groups were the 5th and the 6th decades with a mean age of 46.5. The male-to-female ratio was 1.6 1. The most common symptoms were mucous discharge and defecation difficulty. All lesions involvedthe rectum, and the lower rectum was the most common site. Four diffuse-type lesions showed an extensive involvement up to the sigmoid colon. The most common form of SRUS was the elevated type (44.4%). The ulcerated type accounted for 27.8% of the cases and the flat type, 22.2%. Circumferential involvement of the SRUS was noticed in 3 cases. In 9 cases (50%), pathologic findings missed the characteristics of SRUS and indicated one or a combination of chronic nonspecific inflammation, a chronic ulcer, an inflam-matory polyp, an adenomatous polyp, pseudomembranous colitis, and adenocarcinoma. In three of these cases, a second biopsy was taken with the same results. Based on the clinician' s belief that SRUS was the cause of the lesions, all nine cases were reviewed by the pathologist and a final diagnosis of SRUS was reached. Associated disorders were hemorrhoids, rectoceles, rectal prolapse, perianal fistulas, descending perineum syndrome, and anal fissures. Among them, hemorrhoids and rectoceles were the most common disorders. Four SRUS cases were managed surgically with good results. The surgical treatment was an excision of the lesion itself and/or the correction of the associated disorders. CONCLUSIONS: The histologic characteristics of SRUS are the key to diagnosis, but sufficiently large biopsy specimens are necessary in order to obtain the correct diagnosis. However, the clinical features, including symptoms and associated disorders, plus the characteristic endoscopic findings can produce the correct diagnosis even in cases of insufficiently large biopsy samples or incomplete histologic reports.