Introduction: Colorectal cancer (CRC) is the 3rd leading cause of deaths in the United States.Out of all primary colorectal cancers, adenocarcinoma accounts for the majority of cases.Mucinous and signet ring types are less frequent.Primary signet ring cell carcinoma of the colon is < 1% of all CRC. >96% signet ring carcinoma arise from stomach and rest from other part of GI tract, urinary bladder and breast.
Methods: 29 YO F with no PMH,6 months postpartum, came in with 6 months hx of decreased appetite and 80 lbs weight loss since delivery. Reported intermittent hematochezia with constipation for past 6 months.Reported abdominal pain for few years but never seek medical advice until recently. Used NSAID for almost a year. No Fhx of colon or gastric cancers. Never had colonoscopy or EGD. She is non-smoker and drinks occasionally.CT abd pelvis showed sigmoid wall thickening with para aortic and iliac lymphadenopathy. Her labs were significant with Hb of 9.1 and CEA 384. (AFP- 3.4, CA125 -12.8, CA19-9 -22.4, CA27-29 -37 , CA 15-3 -14.7). Flexible sigmoidoscopy showed ulcerated partially obstructing mass in distal sigmoid colon with 3-4 mm lumen. Biopsy showed adenocarcinoma with signet ring features. Immunohistochemistry tumor cells with CK20+, CDX2+, CK7-, synaptophysin- and chromogranin -.EGD was unremarkable. Pt was diagnosed with M1 disease given para aortic lymphadenopathy.RAS, BRAF, MSI testing is pending.Pt was started on neoadjuvant therapy with FOLFOX regimen given high risk partial obstruction with no clinical signs of obstruction and the plan was follow it with colostomy or stent placement. Discussion: Signet ring carcinoma of colon (SRCC) occurs mostly in young female < 40 YO.SRC cells show high BRAF mutation rate and more prevalent MSI compared to adenocarcinoma. Loss of E cadherin expression is associated with high grade and invasive nature of SRC.Tumor staging is the best predictor of overall prognosis. 5 yr survival rate is 0-12% and disease recurrence is higher compared to adenocarcinoma.Patients with SRCC can benefit from intensified adjuvant chemotherapy given high risk of recurrence and distant metastasis. According to a retrospective study on 22 patients with primary signet ring carcinoma,11 patients were cured with surgical resection.It was found that age, gender,FHx, the size of the tumor, presence of liver metastasis, depth of invasion, and addition of adjuvant as well as neoadjuvant therapies, had no statistically significant effect on the survival period (P> 0.05).
Disclosures: Kushal Shukla indicated no relevant financial relationships. Dhanasekaran Ramasamy indicated no relevant financial relationships.