Jade Law, MD1, Simi Singh, MD2
1University of California Los Angeles - Olive View Medical Center, Sylmar, CA; 2University of California Los Angeles, Los Angeles, CA
Introduction: Colorectal primary signet ring cell carcinoma (PSRCCR) accounts for less than 1% of colorectal cancer cases. PSRCCR most commonly arises in the stomach, but it can arise in the colon, prostate, rectum, and breast. Prognosis is poor as this cancer is usually advanced upon presentation. We present a rare case of PSRCCR diagnosed early and treated with hemicolectomy.
Case Description/Methods: A 72-year-old male with myelodysplastic syndrome and hemochromatosis presented with a positive stool DNA test. Though he was asymptomatic, colonoscopy revealed a 30mm sessile polyp in the ascending colon. Pathology of the polyp showed poorly differentiated signet-ring cell adenocarcinoma without lymphovascular invasion. Full body computed tomography (CT) scan found no evidence of metastatic disease. Carcinoembryonic antigen (CEA) was elevated at 5.3. He was treated for stage IIA disease with a right hemicolectomy. Two months later, PET-CT showed no recurrence, and CEA level was normal at 2.7.
Discussion: PSRCCR of the colon is a rare malignancy that is typically diagnosed at an advanced stage due to the late manifestation of symptoms. Colorectal cancer screening tests can help identify some of these individuals with sensitivities of 79% for fecal occult blood tests, 92% for stool DNA tests, and >95% for colonoscopies .
A third of PSRCCR patients have metastasis on presentation. One hypothesis for the late presentation of PSRCCR is that the cancer spreads through the mucosa and spares mucosal surfaces, leading to fewer symptoms in the early stages . Treatment is focused on surgical resection, neoadjuvant radiotherapy, and adjuvant radiochemotherapy.
In our case, the patient was diagnosed early at stage IIA without lymph node involvement or metastases. His early diagnosis enabled him to have surgical resection that will likely be curative. This remarkable case showcases a rare circumstance of early detection and treatment of PSRCCR.
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 Kim JH, Park SJ, Park MI, Moon W, Kim SE. "Early-stage primary signet ring cell carcinoma of the colon," World J Gastroenterol, 2013; 19(24): 3895-8
Citation: Jade Law, MD; Simi Singh, MD. P0183 - SIGNET RING CELL CARCINOMA OF THE COLON: A RARE FINDING AND CLINICAL REVIEW. Program No. P0183. ACG 2019 Annual Scientific Meeting Abstracts. San Antonio, Texas: American College of Gastroenterology.