(13.07) Neuroendocrine Tumors (NETs) of Small Intestine

Small intestinal neuroendocrine tumors (NETs), though uncommon and typically indolent, pose significant diagnostic challenges due to their subtle clinical presentations and the limitations of traditional imaging techniques. Their diagnosis is further complicated by the variability of symptoms depending on the tumor's site of origin. This case highlights the diagnostic journey for small intestinal NETs and underscores the utility of capsule endoscopy in detecting elusive primary lesions when other modalities fail.

Case(s) Description :

We describe a 44-year-old male with a background of thyroid cancer post-thyroidectomy, presenting with marked anemia detected during routine evaluation for fatigue. A history of chronic anemia and intermittent melena was noted, yet extensive gastrointestinal workups, including upper endoscopy and colonoscopy, had not identified a source of bleeding. Abdominal imaging through CT and MRI revealed multiple liver lesions, with a liver biopsy indicating well-differentiated NETs of intestinal origin. Despite this, the initial gastrointestinal workup did not locate the primary tumor. It was ultimately identified by capsule endoscopy as a small mass in the mid-small bowel.

The patient underwent successful surgical excision of a 3 cm proximal ileal tumor, confirmed as a well-differentiated neuroendocrine tumor grade 2 by pathology. Observation was chosen for the asymptomatic liver lesions, with planned regular monitoring.

 

Discussion :

This case contributes to the body of evidence that while small bowel NETs are becoming more frequently diagnosed, their non-specific clinical profile often leads to delays in identification, potentially advancing disease progression by the time of diagnosis. This report highlights the necessity of considering small intestinal NETs in the differential diagnosis of chronic anemia, occult gastrointestinal bleeding and suggests the integration of capsule endoscopy into the diagnostic algorithm for these patients. The case also prompts a discussion on the individualized management of NETs, considering the asymptomatic nature of certain lesions and the potential benefits of conservative versus interventional strategies.