Smooth muscle tumors of the rectum and anus: a collective review of the world literature.

In this collective review, we have compiled all the reported cases of smooth muscle tumors of the rectum/anus in the world literature from 1959 to 1989. Our goal was to increase the data pool of smooth muscle tumors by adding these new data to that previously collected from 1881 to 1959. We increased the pool for leiomyomas from 89 to 148 and that for leiomyosarcomas from 54 to 215. By doing this, we hoped to make more accurate conclusions about smooth muscle tumors based on this increased data pool. Some interesting findings included three cases in small children that were found in our recent review: a 2-year-old with a leiomyoma and two small infants, aged 12 days and 36 days, with leiomyosarcomas. Again, the findings were probably consistent with an increased data pool. We were also able to find several more cases involving the anal region. We found the highest incidence of leiomyomas to have increased by a decade from the 40-49 year age group to the 50-59 year age group, while among leiomyosarcomas, there was about equal incidence among the 50-59 and 60-69 age groups. We doubt that these represent actual changes in the demographics, but rather that these latter findings are more accurate based on the greater quantity of cases available to us. As a further example, we found no appreciable sex difference; however, we did find more cases reported in females. From our increased data pool, we were able to find 16 more cases that were described as dumbbell-shaped, compared to one that was reported before 1959. Palpable mass, hemorrhage, and pain/discomfort continued as the most common symptoms reported at presentation. With regard to size, the majority of leiomyomas were found to be less than 5 cm in diameter, closely followed by those 5-9 cm. The majority of leiomyosarcomas were 5-9 centimeters at discovery. Most cases of leiomyoma were treated by excision, while most cases of leiomyosarcoma were treated by abdominoperineal resection, a finding consistent with old data. We hope that this paper thoroughly reviews pertinent information about leiomyomas and leiomyosarcomas of the rectum/anus and, in doing so, serves to refresh a few memories, stimulate others, and teach a few.