Ileal Signet Ring Cell Carcinoma Masked by Crohn Disease

Area of Science:

• Gastroenterology
• Oncology
• Pathology

Background:

• Signet ring cell carcinoma (SRCC) is a rare, aggressive adenocarcinoma, typically gastric but occasionally involving the small intestine.
• Crohn disease (CD) involves chronic inflammation, potentially increasing the risk of small intestine adenocarcinoma.
• Early detection of ileal SRCC in CD patients is crucial due to overlapping symptoms and SRCC's aggressive nature.

Observation:

• A 67-year-old male with a 44-year history of ileal Crohn disease presented with new gastrointestinal symptoms.
• Imaging revealed ileal wall thickening, and subsequent ileocolonoscopy identified a terminal ileal stricture.
• Biopsy confirmed signet ring cells, and surgical resection revealed a 2.5-cm ileal mass with metastatic lymph node involvement.

Findings:

• Histopathology confirmed poorly differentiated adenocarcinoma with signet ring cell features in the ileum.
• Metastatic disease was identified in one mesenteric lymph node.
• The patient initiated adjuvant chemotherapy post-surgery.

Implications:

• This case underscores the possibility of metastatic ileal SRCC in patients with long-standing Crohn disease.
• Despite a low absolute risk, active surveillance for small bowel adenocarcinoma in CD patients is recommended.
• Recognizing overlapping symptoms between SRCC and CD is vital for timely diagnosis and management.