Ileal Signet Ring Cell Carcinoma Masked by Crohn Disease

摘要

Background: Signet ring cell carcinoma (SRCC) is a rare, highly malignant adenocarcinoma that generally involves the stomach; ileal involvement is uncommon. Crohn disease (CD) is associated with long-standing inflammation that may predispose to small intestine adenocarcinoma.Case Report: A 67-year-old male with ileal CD since age 23 years, maintained in remission by mesalamine, presented with mild intermittent attacks of abdominal cramping, an increase in bowel movements from 3 to 5 daily, and bloating for 3 months. Computed tomography enterography with contrast enhancement demonstrated 2 segments of ileal wall thickening. Colonoscopy performed 7 years prior was unremarkable. The patient received oral prednisone with mild symptomatic improvement; he declined biologics. Ileocolonoscopy 1 month later revealed a nontraversable terminal ileal stricture 15 cm from the ileocecal valve. Biopsy demonstrated signet ring cells infiltrating the lamina propria. The patient underwent laparoscopic ileocecectomy and ileocolic anastomosis. Histopathology of a 2.5-cm ileal mass showed poorly differentiated adenocarcinoma with mucin production and signet ring cell features. One metastatic mesenteric lymph node was identified. Adjuvant chemotherapy was initiated.Conclusion: This case of metastatic ileal SRCC occurred in the setting of long-standing, clinically controlled CD. Although the absolute risk of small-bowel adenocarcinoma in CD is low, active surveillance for small-bowel adenocarcinoma in patients with longstanding CD may be prudent, given the overlapping symptomology of SRCC and CD, the aggressiveness of SRCC, and the association of SRCC with subclinical inflammation. Keywords: Carcinoma–signet ring cell , Crohn disease , ileal neoplasms , inflammation , intestine–small INTRODUCTIONSmall-bowel malignancies are rare, accounting for 3% of gastrointestinal tract neoplasms.~(1) Adenocarcinomas represent 25% to 40% of small-bowel neoplasms.~(2) Signet ring cell carcinoma (SRCC) is a rare adenocarcinoma that generally involves the stomach but can involve other organs, including the small intestine.~(3) SRCC is poorly differentiated and has a poor prognosis.~(4,5)Crohn disease (CD) is a well-known risk factor for intestinal cancer,~(3) arguably because of CD-associated inflammation.~(6) We report a case of ileal SRCC in a patient with long-standing, clinically controlled CD.CASE REPORTA 67-year-old male with ileal CD since age 23 years, maintained in remission by mesalamine, presented with mild intermittent attacks of abdominal cramping, an increase in bowel movements from 3 to 5 daily, and bloating for 3 months. Abdominal examination revealed mildly diffuse tenderness with hyperactive bowel sounds. Leukocyte count was 8.3 cells/μL, erythrocyte sedimentation rate was 33 mm/h, and C-reactive protein was 5.6 mg/L.Computed tomography (CT) enterography with contrast enhancement demonstrated 2 segments of ileal wall thickening (Figure 1). Colonoscopy performed 7 years prior was unremarkable. The patient took oral prednisone 40 mg/day for 1 week, followed by gradual tapering for 1 month for suspected partial inflammatory small-bowel obstruction. He reported mild symptomatic improvement. The patient declined biologics. Open in a separate windowFigure?1. (A and B) Axial section of computed tomography enterography demonstrates wall thickening of several loops of the ileum (arrows).