Duodenal subepithelial hyperechoic lesions of the third layer: Not always a lipoma

Abstract

Endoscopic ultrasonography is the most accurate procedure for the evaluation of subepithelial lesions. The finding of a homogeneous, hyperechoic, well-delimited lesion, originating from the third layer of the gastrointestinal tract (submucosa) suggests a benign tumor, generally lipoma. As other differential diagnoses have not been reported, echoendoscopists might not pursue a definitive pathological diagnosis or follow-up the patient. This case series aims to broaden the spectrum of differential diagnosis for duodenal hyperechoic third layer subepithelial lesions by providing four different and relevant pathologies with this echoendoscopic pattern.

Keywords: Duodenum; Endoscopic ultrasonography; Endoscopic ultrasound-guided fine needle aspiration; Lipoma; Subepithelial tumor.

Figure 1

Endoscopic ultrasonography and cytology findings of a renal cell carcinoma metastasis. A: Hyperechoic mass in the duodenal bulb, apparently originating from the third layer. Adjacent, a small lymph node is noted; B-E: Fine-needle aspiration cell blocks, × 400 magnification; Hematoxylin and eosin staining showing clear cell aggregates (B). Positive immunostaining for cytokeratin AE1/AE3 (C), vimentin (D) and CD10 (E): consistent with an epithelial carcinoma of renal origin.

Figure 2

Endoscopic ultrasonography and pathological findings of an ampullary carcinoma. A: Mildly hyperechoic third-layer lesion adjacent to the ampulla, compressing the bile duct; B, C: Fine-needle aspiration, × 400 magnification; B: Smears with acinar groups, irregularly distributed nuclei, coarse chromatin, conspicuous nucleoli (Papanicolaou); C: Cell-block preparation of aspirated sample [hematoxylin and eosin (HE)]; D: Surgical pathology specimen confirming the full excision of an ampullary carcinoma; E: Ampullary area well-differentiated adenocarcinoma, HE × 25; F: HE × 100.

Figure 3

Endoscopic, endoscopic ultrasonography and pathological findings of hamartomatous polyp. A: Semipedunculated polyp in the second portion of the duodenum; B: Longitudinal view of the polyp’s stalk-originating from the duodenal wall; C: Top of the polypoid lesion-cross-sectional view; D: Hamartomatous polyp, HE × 25.

Figure 4

Endoscopic, endoscopic ultrasonography and pathological findings of gangliocytic paraganglioma. A: Slightly hyperechoic lesion of the third layer of the duodenal wall; B-E: Endoscopic ultrasonography-fine needle aspiration with cytological features suggestive of GIST; B: Few fragments of loose mesenchymal spindle cell tissue fragments (Papanicolaou staining × 100); C: Cell block preparation of aspirated material, discrete nuclear atypia [Hematoxylin and eosin (HE) × 100]; D: Most cells stain positive for CD117 (× 400); E: Rare cells stained with CD34 (× 400); F: Resection of the subepithelial lesion using endoloop; G-I: Histopathological analysis of the resected tumor; G: Duodenal gangliocytic paraganglioma (HE × 25); H: Duodenal gangliocytic paraganglioma (HE × 200); I: Sustentacular S-100 positive cells documented (S100 ×100). GIST: Gastrointestinal stromal tumor.