Introduction: Small bowel adenocarcinoma (SBA) accounts for less than 5% of all gastrointestinal malignancies. Crohn's disease (CD) is a well-known risk factor for developing small bowel adenocarcinoma. CD-associated small bowel adenocarcinoma tends to develop at a younger age, mainly involves distal jejunum and terminal ileum, and is male predominant. SBA in the setting of CD is incidentally found after surgical resection. We present a rare case of small bowel adenocarcinoma as the first manifestation of Crohn's disease in a patient with a history of celiac disease.
Case Description/Methods: We present a 35-year-old female with a remote history of biopsy proven celiac disease and a history of multiple small bowel strictures dating back to the age of 16, which was thought to be due to ulcerative jejunitis. She never underwent an exploratory laparoscopy for tissue diagnosis. She was placed on a gluten-free diet with improvement in her symptoms. She presented to our clinic with episodes of nausea and vomiting that started five years ago. Labs done at that time were unremarkable except for mildly elevated fecal calprotectin. CT scan abdomen pelvis showed multiple strictures throughout the small bowel, including the proximal jejunum. Colonoscopy with terminal ileal biopsy was normal. She was then seen by surgery and underwent an exploratory laparoscopy with resection of two small bowel strictures and stricturoplasty of the other two strictures. Pathology showed active jejunitis and non-necrotizing granulomas consistent with Crohn's disease and findings of well differentiated mucinous adenocarcinoma in the first stricture and moderate to poorly differentiated adenocarcinoma in the second stricture. She was staged to be T2 N0 MX. She was started on adalimumab and has been on remission.
Discussion: Our case is unusual in that there are very few reported cases of SBA in undiagnosed CD. Data concerning SBA in CD is based on case reports, small retrospective series and literature reviews. SBA in CDs strictures poses a diagnostic challenge as it is difficult to differentiate a malignant stricture from an inflammatory stricture using conventional investigation modalities. As such, it is essential for surgeons to maintain a high index of suspicion for occult SBA and careful investigation with frozen section and/or resection for suspicious findings. Also, our case is exceptional as the diagnosis of inflammatory bowel disease could not be established at the time when the patient sought medical care.
