In adults, rectal leiomyosarcoma is uncommon, and anal leiomyosarcoma is even more rare. We report one patient with anal leiomyosarcoma and one patient with a biphasic clinical history, with three occurrences of perineal leiomyosarcomas after surgically resected rectal leiomyoma. We discuss the characteristics of these rare entities based upon a review of the literature.

Colorectal perforation is a serious complication of barium-enema examination, as the resultant contamination of the intraperitoneal or extraperitoneal space may result in a severe septic course. Between 1 October 1993 and 30 September 1996, four patients had colorectal injuries after barium-enema examinations at the Far Eastern Memorial Hospital, Taipei, Taiwan. Their mean age was 80 years and three of them died, despite the implementation of early and aggressive treatment. To examine the differences between this high crude mortality rate and reports of zero mortality, we retrospectively analyzed the data with the well established predictive surgical scoring system, the Physiological and Operative Severity Score for the enUmeration of Morbidity and mortality (POSSUM), to estimate the potential risk of death in these four patients.

Adult midgut rotational anomalies are difficult to diagnose. Any symptoms present in adults may be the result of intermittent volvulus of the midgut. Successful outcome of this clinical condition depends on prompt diagnosis and timely surgical intervention. Computed tomography (CT) is useful in early identification of these lesions in the abdomen. However, the specific CT signs, the "superior mesenteric vein rotation" sign and the "whirl" sign, are easy to overlook if not kept in mind, as occurred in one of our two patients. In the other patient, CT played the major role in preoperative diagnosis.

Adult intussusception is uncommon and varies considerably from the more common occurrence of this disorder in infants and children. Although lipoma represents the most common benign tumor of the colon, it is a relatively rare cause of gastrointestinal symptoms. A rare case of adult intussusception of the descending colon caused by a giant lipoma is presented and discussed.