Presentation
Abdominal pain, melena.
Patient Data
Ulcerating, exophytic mass projecting from the superior aspect of the 3rd portion of the duodenum.
Displacement and encasement of SMA. Compression and possible segmental occlusion of SMV just before confluence.
Subtle small intermediate attenuation lesion in the periphery of hepatic segment 3. Other small liver cysts.
Exophytic ulcerative mass projecting from superior aspect 3rd portion of the duodenum, with similar findings as on the CT.
Small segment 3 lesion is quite subtle.
Whole body PET (legs were imaged but cropped from this series due to image # constraints). No primary lung, skin, head/neck tumor.
Intense uptake in the duodenal mass. Small liver lesion in segment 3.
Pathology report
Duodenal mass biopsy: Squamous carcinoma in multiple fragments, present in the deeper portions of each fragment, undermining uninvolved superficial duodenal mucosa.
Case Discussion
Primary small bowel squamous cell carcinoma is exceedingly rare, with 22 cases reported in the literature.
The duodenum is the most commonly site. Normally there are no squamous cells in the small bowel, but it is postulated that malignant transformation of heterotopic squamous cells (such as in a diverticulum), pluripotent stem cells, or squamous metaplasia may be responsible.
Given the exophytic, ulcerative appearance of the tumor, it may be that the tumor arose from an intestinal duplication.
Whole body PET-CT confirmed no other primary tumor or other sites of disease besides the hepatic segment 3 lesion.