A subepithelial lesion turns up in the second part of the duodenum and is referred for discussion. Reach for EUS? Resect it? Or can the diagnosis be made at the endoscope, in a couple of minutes, with the kit already in your hand? This short case works through the reasoning step by step — orientation against the major papilla, confirming the lesion is subepithelial rather than mucosal, testing mobility, the pillow sign, and the naked-fat sign that seals the diagnosis of lipoma.
The compression (pillow sign) test flowing into the naked-fat reveal — the self-contained diagnostic climax of the case, ideal for a social teaser.
A subepithelial lesion turns up in the second part of the duodenum and is referred for discussion. Reach for EUS? Resect it? Or can the diagnosis be made at the endoscope, in a couple of minutes, with the kit already in your hand?
This short case works through that reasoning step by step.
"Anything that you think might be invasive, see if it's mobile."
The lesion sits in the second part of the duodenum — possibly the third. With a transparent cap on the scope, the major papilla is straightforward to identify, and the lesion lies distal to it. Holding the minor papilla and the underlying biliary and pancreatic anatomy in mind frames exactly where you are before any instrument goes near the lesion.
"Push into it like you're laying on a pillow … can you compress it?"
Look at the surface. The mucosa draped over the lesion is identical to the mucosa around it — the same duodenal lining covering a bulge, with no surface change of its own. That argues against a mucosal lesion and points to something subepithelial.
"If you think it's a lipoma, then you can confirm by getting fat from inside it."
“Anything that you think might be invasive, see if it’s mobile.”
A freely mobile lesion is unlikely to be invasive or deeply tethered. You can assess this without even opening the forceps: bring a closed biopsy forceps alongside and nudge the lesion. Here it moves easily, sitting on a fold of mucosa rather than anchored into the wall.
“Push into it like you’re laying on a pillow … can you compress it?”
Press into the lesion. A lipoma gives way — the cushion, or pillow, sign. This one compresses readily. Combined with the appearance and the mobility, lipoma moves to the top of the differential.
This is the confirmatory step. Biopsy repeatedly on the same spot — open, close, open, close — to unroof the lesion. Beneath the mucosa, yellow fatty tissue becomes clearly visible. That is the naked-fat sign, and it confirms a lipoma.
Once you see fat, you are finished. No EUS, no resection, no further work-up — a benign duodenal lipoma needs nothing more. The rest of the subepithelial differential behaves differently: GISTs, neuroendocrine tumours and ectopic pancreas more often look white, feel firmer, or carry surface irregularity, and they neither compress nor yield fat.
Orient, confirm subepithelial, test mobility, compress, unroof. A structured bedside sequence turns a “refer for discussion” lesion into a confident diagnosis in three minutes.
Watch the full case above.
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