Retrorectal tumors: A diagnostic and therapeutic challenge

PURPOSE: Tumors occurring in the retrorectal space are heterogeneous and uncommon. The utility of newer imaging techniques has not been extensively described, and operative approach is variable. This study examined the diagnosis, treatment, and outcome of retrorectal tumors at a tertiary referral center. METHODS: Patients with primary, extramucosal neoplasms occurring in the retrorectal space were identified using a prospectively maintained, procedural database of all adult colorectal surgical patients (1981-2003). Patients also were incorporated from the gynecologic oncology service. Exclusion criteria included inflammatory processes, locally advanced colorectal cancer, and metastatic malignancy. Medical records, radiology, and pathology reports were reviewed retrospectively. RESULTS: Thirty-four patients with retrorectal tumors were treated. Malignant tumors comprised 21 percent. Older age, male gender, and pain were predictive of malignancy (P < 0.05). Sensitivity of proctoscopy was 53 percent; this increased to 100 percent with the use of transrectal ultrasound. Accuracy of magnetic resonance vs. computed tomographic imaging for specific histologic tumor type was 28 vs. 18 percent, respectively. Surgical approach was anterior (n = 14), posterior (n = 11), and combined abdominoperineal (n = 9). Eleven patients required en bloc proctectomy. Patients undergoing posterior resection had lower blood loss and required fewer transfusions (P < 0.05). All benign tumors were resected with normal histologic margins and none recurred (median follow-up, 22 months). All patients with malignancy had recurrence/recrudescence of their disease. For these patients, median disease-free and overall survivals were 38 and 61 months, respectively. CONCLUSIONS: Retrorectal tumors remain a diagnostic and therapeutic challenge. Pain, male gender, and advanced age increase the likelihood of malignancy. Various imaging modalities are useful for planning resection but cannot establish a definitive diagnosis. Whereas benign retrorectal tumors can be completely resected, curative resection of malignant retrorectal tumors remains difficult.