Metastatic small bowel neuroendocrine tumor


The avid enhancement of the terminal ileum initially caused confusion with a possible arteriovenous malformation (AVM) being considered however this area was biopsied on colonoscopy prior to the CT examination and it was reasoned that the lack of brisk bleeding after sampling made AVM less likely. The presence of a mesenteric soft tissue mass with apparent indrawing of the surrounding vessels also supported the differential of neuroendocrine tumor.

Following confirmation of avidity on Octreotide scan and absence of any distant avid disease the patient proceeded to right hemicolectomy. Histology and immunohistochemistry confirmed a well-differentiated neuroendocrine tumor breaching the serosal surface, with a mesenteric tumor deposit and 10/17 involved draining nodes (including the highest sampled node) giving a pathological staging of pT4 pN1 R0 resection. Vascular and perineural invasion was also present on histology.

The MRI liver was performed some 5 months after the CT enterography (3 months post-surgery) to ensure the liver lesions on CT were indeed benign. The hypoattenuating foci on CT did correspond with benign entities, though the MRI did demonstrate suspicious lesions as described above. A subsequent gallium-68 DOTATATE nuclear medicine scan (imaging not shown here) showed avidity in the two largest lesions which were described on MRI, it was felt the third lesion was too small to have demonstrated avidity and is still suspicious of a metastasis.

At present the patient is under clinical follow up with plan for repeat MRI liver in the near future at the time of writing.

Acknowledgements to Dr Rachel Allard, Dr Adam Laverty and Dr Hssein Al-Chalabi.

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