Keywords
endoscopic ultrasound - EUS - leiomyoma - subepithelial lesion
An 88-year-old man with multiple comorbidities underwent urgent cholecystectomy for
acute-on-chronic gangrenous cholecystitis. A preoperative contrast-enhanced abdominal
computed tomography scan identified a 30 × 26 mm hypodense solid nodular lesion between
the descending part of the duodenum and the pancreatic head, which showed both a hyper-
and a hypovascular component, suspected to be neoplastic ([Fig. 1]). Esophagogastroduodenoscopy ruled out mucosal duodenal lesions or infiltrative
neoplasia. Endoscopic ultrasound (EUS) revealed an oval hypoechoic lesion with slightly
heterogeneous pattern and mild “fat stranding” originating from the muscularis propria
([Fig. 2A]). The evaluation of microvasculature and parenchymal perfusion with EUS detective
flow imaging (EUS-DFI) confirmed the mixed vascularity patterns ([Fig. 2B]), while elastography did not show increased stiffness. Based on US findings and
lesion location, the main hypothesized diagnosis was a type IV gastrointestinal stromal
tumor (GIST). A EUS fine-needle biopsy (EUS-FNB) was performed using a 22-gauge needle
(Acquire, Boston Scientific, Marlborough, MA, United States) with a fanning technique
(2 passes) to sample the hypo- and hypervascular components.
Fig. 1 Contrast-enhanced abdominal computed tomography revealed a nodular lesion between
the descending part of the duodenum and the pancreatic head. (A) Arterial phase. (B) Portal phase.
Fig. 2 (A) An endoscopic ultrasound showed a slightly inhomogeneous hypoechoic lesion with
mild “fat stranding” originating from the muscularis propria. (B) The evaluation of microvasculature and parenchymal perfusion with detective flow
imaging demonstrated mixed vascularity patterns (a hypo- and a hypervascular region).
(C) Elastography revealed an average texture.
The histopathological examination revealed a benign spindle cell tumor with smooth
muscle differentiation with no evidence of atypia or necrosis compatible with a diagnosis
of leiomyoma (α-smooth muscle actin + , desmin + , S100-, CD34-, DOG1-, CD117, Ki-67
< 1%). Therefore, no treatment or follow-up was needed.
As demonstrated in our case, the differential diagnosis of subepithelial lesions (SELs),
especially those with atypical features, represents a challenge in clinical practice.[1]
[2] Advanced techniques such as EUS-DFI, elastography, and EUS-FNB are essential to
achieve an accurate diagnosis by delineating the morphological features, originating
wall layers, and histological characteristics (when needed).[3]
Gastrointestinal leiomyomas are benign tumors originating from smooth muscle cells,
mainly occurring in the esophagus.[4] Duodenal leiomyomas are rare (<5% of all gastrointestinal leiomyomas). While the
exact pathogenesis remains uncertain, a possible chronic inflammatory pathway has
been described and may be considered for atypical sites as in this case.[5]
Leiomyomas are typically asymptomatic and incidentally discovered during imaging.
They can mimic pancreatic or duodenal malignancies, when large, ulcerated, or with
necrosis. EUS is essential for histopathological diagnosis.
In summary, our case supported the pivotal role of EUS-FNB in the differential diagnosis
of SELs with atypical sites and findings, preventing unnecessary surgical procedures
in high-risk patients.
