Early-stage primary signet ring cell carcinoma of the colon

Abstract

Primary signet ring cell carcinoma of the colorectum detected at an early stage is very rare; most cases are detected at an advanced stage. Therefore, its prognosis is poorer than that of ordinary colorectal cancer. A 56-year-old Korean man was seen at this hospital for management of signet ring cell carcinoma of the colon. Colonoscopic examination revealed a IIa-like, ill-defined and flatly elevated 9-mm residual tumor in the cecum. Endoscopic mucosal resection was preformed. Pathological examination of the resected specimen revealed signet ring cell carcinoma that had invaded the lamina propria without venous or perineural invasion. Abdominal computed tomography (CT) and positron CT showed no evidence of primary lesions or distant metastasis. An additional laparoscopic right-hemicolectomy was performed; no residual tumor or lymph node metastasis was found. We report a case of primary signet ring cell carcinoma of the colon detected at an early stage and provide a review of the literature.

Keywords: Colon carcinoma; Early stage; Endoscopic mucosal resection; Primary carcinoma; Signet ring cell carcinoma.

Figure 1

Initial colonoscopic findings (from another hospital). Colonoscopic examination revealed a IIa-like, ill-defined and flatly elevated 5-mm tumor in the cecum (arrow).

Figure 2

Colonoscopic findings at this hospital. A: Colonoscopic examination revealed a IIa-like, ill-defined and flatly elevated 9-mm residual tumor in the cecum; B: Narrow band imaging shows the lesion more clearly.

Figure 3

Resected specimen by endoscopic mucosal resection. The resected specimen was 10 mm in diameter.

Figure 4

Scanning view of the endoscopic mucosal resection site. Histologically, the resected specimen showed diffusely infiltrated signet ring cells in the lamina propria without venous or perineural invasion. A: hematoxylin/eosin staining, × 40; B: hematoxylin/eosin staining, × 400.

Figure 5

Gross findings. The mucosal surface of the cecum showing an ill-defined irregularly-shaped scar (probably the endoscopic mucosal resection site). The remaining mucosa showing multiple polyps and previous polypectomy sites.