Abstract
A 65-year-old woman showed anemia at a health examination and visited a nearby clinic, where she was diagnosed with transverse colon leiomyosarcoma on lower gastrointestinal tract endoscopy. She was referred to our hospital, where she underwent laparoscopic partial resection of the transverse colon in September 2013. Histopathological examination of the resected specimen diagnosed leiomyosarcoma, and the surgical margins were negative. A mass 20 mm in diameter was observed in the transverse colon on abdominal contrast-enhanced CT performed in January 2014, with a diagnosis of recurrent leiomyosarcoma. In March of the same year, she underwent open right hemicoloectomy including D2 dissection. A tumor was observed in the ascending mesocolon, 5 mm proximal to the previous anastomosis. Intra- and extramural metastases were diagnosed from histopathological examination. When leiomyosarcoma is treated surgically, total resection of the tumor is a common method of ensuring negative margins, but this case suggests the need to ensure an adequate resection distance from the tumor. We encountered and report herein a case of transverse colon leiomyosarcoma with a very rare form of metastasis.
