P4653 - Unmasking the Rarity: A Case of Primary Signet-Ring Cell Carcinoma of the Colon in a Young Female

Susan Kais, MD, Matthew Soliman, , Addie Schumacher, MD, Madison Lange, ANPC
University of Cincinnati, Cincinnati, OH

Introduction:

Primary signet-ring-cell carcinoma of the colon and rectum (PSRCCR) is a rare & aggressive subtype of colorectal cancer, accounting for 0.1–1% of cases. It is associated with poor prognosis, advanced disease at diagnosis, high rates of peritoneal metastasis, & lower survival rates compared to other colorectal cancers. First identified in 1951, PSRCCR is classified as a variant of mucinous adenocarcinoma, typically presenting as diffuse, circumferential bowel wall thickening that can mimic IBD, leading to delayed diagnosis. Its aggressive nature often results in high rates of lymphovascular invasion & peritoneal dissemination, occurring in over 50% of cases. Although most cases occur in older adults, primary cases in younger individuals are exceptionally rare. Here, we report an unusual case of PSRCCR in a 29-year-old female.

Case Description/

Methods:

Our patient is a 29-year-old female with a medical history of organ transplantation, hypertension, type 2 diabetes, & recent cholecystectomy, who presented with severe abdominal pain, obstipation, & vomiting. CT revealed a small bowel obstruction & an 8 cm cecal mass involving the ileocecal valve, with pericecal soft tissue infiltration & lymphadenopathy. Differential diagnoses included a primary colonic neoplasm or lymphoproliferative neoplasia. The patient underwent exploratory laparotomy for mass resection & right hemicolectomy. Biopsies indicated poorly differentiated grade 3 signet-ring cell carcinoma with mucinous features, classified as pT4a pN2b cM1c due to peritoneal metastasis. There was no loss of mismatch repair proteins, & the probability of microsatellite instability was low. PET scan suggested possible peritoneal carcinomatosis, & chemotherapy was initiated.

Discussion:

PSRCCR is particularly uncommon in younger populations, with limited case reports highlighting the challenges in diagnosis & management. The rarity in individuals under 30 is likely due to the typical age distribution of colorectal cancer, which predominantly affects older adults. The distinct histological features of PSRCCR contribute to delayed diagnosis, as symptoms may mimic other gastrointestinal conditions. Increased awareness among clinicians is essential for timely identification of PSRCCR in younger patients presenting with gastrointestinal symptoms. This case underscores the need for prompt evaluation & appropriate diagnostic imaging to facilitate early diagnosis & intervention, ultimately improving outcomes for affected individuals.

Disclosures:
Susan Kais: Abbvie – Advisor or Review Panel Member, Advisory Committee/Board Member, Consultant, Speakers Bureau. BMS – Advisor or Review Panel Member, Advisory Committee/Board Member, Speakers Bureau. Janssen – Advisor or Review Panel Member, Advisory Committee/Board Member, Speakers Bureau.
Matthew Soliman indicated no relevant financial relationships.
Addie Schumacher indicated no relevant financial relationships.
Madison Lange indicated no relevant financial relationships.

Susan Kais, MD, Matthew Soliman, , Addie Schumacher, MD, Madison Lange, ANPC. P4653 - Unmasking the Rarity: A Case of Primary Signet-Ring Cell Carcinoma of the Colon in a Young Female, ACG 2025 Annual Scientific Meeting Abstracts. Phoenix, AZ: American College of Gastroenterology.