Case 1 : A 69-year-old female visited another hospital because of hematochezia. Colonoscopy showed an ascending colon tumor revealed prominent submucosal growth during a month. The tumor invading into the muscularis propria showed a low echoic mass by endoscopic ultrasonography (EUS) . She was admitted to our hospital and underwent right hemicolectomy. The histological findings of the resected specimen demonstrated that mucinous adenocarcinoma was invaded to the subserosa, but no cancer tissue was existed in the lamina propria.
Case 2 : A 43-year-old male visited our hospital with positive for occult blood in stool. Colonoscopy showed the broad based mass covered with red granular mucosa was located in the sigmoid colon. EUS findings represented a low echoic tumor with subserosal invasion. Histologically, mucinous adenocarcinoma invaded into the subserosa was mostly covered with noncancerous mucosa except for the center of the tumor.
Colorectal cancer with prominent submucosal growth is rare. Although it is difficult to distinguish the tumor from submucosal tumor and metastatic cancer, EUS can provide useful information for the differentiation between those tumors, and also for the diagnosis of the depth of cancerous invasion.
