Undiagnosed Case of Signet Ring Cell Colorectal Carcinoma: A Case Report and Review of the Literature

Abstract

Abstract Colorectal cancer is third most common cancer in the United States. Adenocarcinoma is the most common type of large intestine cancer. Signet ring cell adenocarcinoma (SRCC), a subtype of adenocarcinoma, is characterized by the tumor cells production of intracellular mucin. SRCC has several unique characteristics: it more commonly presents in younger patients, is located in the right hemi-colon or rectum, invades the lymphatic system, and metastasizes to the peritoneum. We describe the case of a 46-year-old female with undiagnosed SRCC who previously presented to an outside hospital, where she underwent both Computed Tomography imaging and a colonoscopy. Colonoscopy is the gold standard in diagnosing colorectal cancer, with a sensitivity of over 95%. Nevertheless, the patient’s colonoscopy biopsy was negative for malignancy, likely because the operator did not reach the tumor secondary to obstruction. Forty-two days later the patient presented to our hospital, where she underwent a right hemi-colectomy and resection of the tumor encompassing the ileocecal valve, cecum, and the ascending colon. Following this non-curative operation, the patient started chemotherapy and is progressing as anticipated.