Colonic metastasis of dermatofibrosarcoma protuberans detected by colonoscopy

Colonic metastasis from dermatofibrosarcoma protuberans (DFSP) is exceedingly rare, and few reports have described its characteristic endoscopic features. Here, we report the case of a 66 year-old woman with a history of DFSP who presented with a colonic lesion detected during colonoscopy. The lesion appeared as a firm, subpedunculated, elevated mass in the descending colon. At the initial examination, the lesion was covered with intact epithelium; however, at a follow-up examination 6 weeks later, the surface epithelium had sloughed off. Endoscopic ultrasonography revealed a predominantly submucosal nodule. Endoscopic mucosal resection yielded sufficient tissue to establish a definitive diagnosis of metastatic DFSP. This case highlights not only the exceptional rarity of colonic metastasis from DFSP but also the diagnostic value of careful endoscopic evaluation-including the observation of dynamic changes in lesion morphology-as well as the role of endoscopic resection in obtaining adequate diagnostic tissue.