[Leiomyomatosis of the colon: case report and literature review].

We present the findings of a 67 year old male patient with an intestinal leiomyomatosis localized in the rectum. To our knowledge, this is the fifth case of intestinal leiomyomatosis reported so far. The most characteristic findings of this rare disease include a cuff-like tumorous proliferation of smooth muscle within the bowel wall which may extend into extramural tissue and result in a stenosis of a longer bowel segment. Because of severe obstructive symptoms over 5 years, the patient had to undergo surgery with resection of the rectum. The histological examination revealed a morphology and immunophenotype comparable to usual leiomyomas with the exception of hyalinosis-like changes in the blood vessels, apparently a special feature of leiomyomatosis. A novel finding in our case was the occurrence of skeinoid fibers which have so far only been reported in gastrointestinal stromal tumors.