Tumors of the Rectum and Anal Canal

Abstract

This collective review includes all available case reports of smooth muscle (stromal) tumors of the rectum and anal canal in the world literature. When compiling this review we endeavored to present cumulative and recently collected data of both benign and malignant smooth muscle tumors found in the literature spanning the period from 1881 to 1996, which totaled 432 leiomyomas (LMs) and 480 leiomyosarcomas (LMSs) of the anus and rectum. The peak age of frequency for LMs was 40 to 59 years and 50 to 69 years for LMSs; men were slightly more likely to develop both benign and malignant anorectal smooth muscle tumors than women. Intraluminal growth of both LMs and LMSs was more frequently seen than extraluminal or intramural patterns, and tumors were more likely to be found in the rectum than in the anus. Patients with LMs presented most commonly with gastrointestinal (GI) bleeding, a palpable mass, or anorectal pain. As with smooth muscle tumors in other areas of the alimentary tract, symptoms likely persisted for less than 1 year prior to diagnosis. As was also the case for these neoplasms in other GI locations, LMSs tended to be larger than LMs. Approximately 20% of LMSs reported from 1881 to 1996 had metastasized at diagnoses. The local recurrence rate for resectable tumors was more than 80%, exceeding the propensity of LMSs in other areas of the GI tract to recur.

A population-based study of colorectal cancer histology in the United States, 1998–2001

“…In addition to the histologic types listed earlier, more sarcomas occurred in individuals under age 40. These results with regard to sarcomas are somewhat inconsistent with previous studies reviewing case reports of gastrointestinal leiomyosarcomas diagnosed from 1881 to 1996 and published by Hatch et al 35,36 Those studies reported the peak age of frequency of leiomyosarcomas to be 50-69 years. 35 This inconsistency in results could be due to differences among populations or variations in methodology.…”

“…The Hatch et al leiomyosarcoma study found that only about 20% of rectal and anal canal tumors had metastasized at diagnosis, a finding consistent with our results for sarcomas. 35 Carcinoid tumors were also most often diagnosed at localized stage and See Table 2, footnote 1 (indicated with *) for data source. Table 2, footnote 1 (indicated with *) for data source.…”

“…35,36 Some CRC histologies present with particular anatomic subsite, stage, and grade patterns. These patterns are important for prognosis.…”

Treatment of rectal leiomyoma by endoscopic resection

“…These tumors are originated in the smooth muscle fibers of mucosa or muscular fibers of the circular and longitudinal layers of the rectal wall 4,8,12,15,16 or blood vessel walls 4,12,16 . They occur especially in the distal two-thirds of the rectum 13,15 and tend to present intraluminal growth 7 . Most cases are asymptomatic 1,9,10,17,18 , and for this reason, found incidentally while performing endoscopic procedures 1,3,5,9,10,16,18,19 .…”

“…Leiomyoma and leiomyosarcoma, tumors of smooth muscle, can occur in the whole gastrointestinal tract [1][2][3] , affecting more frequently organs such as the stomach (65%) and small bowel (25%) 4 and rarely found in the rectum 1,[5][6][7][8][9][10][11][12][13][14] . Leiomyoma of the rectum occurs in approximately 1 out of 2,000-3,000 rectal tumors 4,8 and, although such occurrence is rare, many cases have been reported in the literature 1,4-14 since its first histopathological confirmation described by Malassez in 1872 4 .…”