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.
Adenocarcinoma ; Adenomatous Polyps ; Biopsy ; Classification ; Colitis ; Colon, Sigmoid ; Defecation ; Diagnosis* ; Diagnostic Errors ; Enterocolitis, Pseudomembranous ; Fistula ; Hemorrhoids ; Humans ; Inflammation ; Mucous Membrane ; Perineum ; Polyps ; Prolapse ; Rare Diseases ; Rectal Prolapse ; Rectocele ; Rectum ; Ulcer*

BACKGROUND AND AIM: While detection and removal of polyps on the basis of the adenoma-carcinoma sequence has been a principal procedure for endoscopists, a new type of early colorectal cancer has been recognized and has become a hot issue. This new ailment is a depressed-type early colorectal cancer, which has the characteristics of rapid growth and early invasion of the submucosa. Though once considered to be mere conjecture, many researchers claim that this cancer is a de novo carcinoma despite of its rare occurrence. Recently, 4 depressed-type neoplastic lesions were presented, which signifies the importance of recognizing that this type of cancer exists and is characterized by rapid growth and early invasion of the submucosa. METHODS: The 4 recently experienced depressed neoplastic lesions were reviewed and analyzed with respect to their endoscopic and clinicopathologic characteristics. The sizes of the lesions were measured in the fully inflated state of the bowel by using an endoscopic ruler. RESULTS: The sites of predilection were the descending and sigmoid colon. All of the lesions were under 10 mm, with 75% being below 5 mm. The largest lesion was an 8-mm, well-differentiated mucosal carcinoma. The overall malignancy rate was 25%. Light redness was observed in all patients. Distortion with air transformation of the mucosal fold was also recognized in all the patients. The main treatment was endoscopic mucosal resection, which amounted to 50%. CONCLUSIONS: Depressed colorectal neoplasms are real. They can be determined by their characteristic endoscopic features, such as light redness and distortion with air transformation of the mucosal fold. Because of their characteristics of rapid growth and early invasion of the submucosa, it is important to detect and manage them in an early stage, when their sizes are below 10 mm.
Colon, Sigmoid ; Colorectal Neoplasms* ; Humans ; Polyps