Diagnosis of ectopic pancreas by endoscopic ultrasound with fine-needle aspiration

Abstract

Aim: To study the clinical, endoscopic, sonographic, and cytologic features of ectopic pancreas (EP).

Methods: This was a retrospective study performed at an academic referral center including two hospitals. Institutional review board approval was obtained. Patients referred to the University Hospital or Denver Health Medical Center Gastrointestinal Endoscopy Lab for gastroduodenal subepithelial lesions (SEL) with a final diagnosis of EP between January 2009 and December 2013 were identified. Patients in this group were selected for the study if they underwent endoscopic ultrasound (EUS) with fine-needle aspiration (FNA) or deep biopsy. A review of the medical record was performed specifically to review the following information: presenting symptoms, endoscopic and EUS findings, computed tomography or magnetic resonance imaging findings, pathology results, procedure-related adverse events, and subsequent treatments after EUS-FNA. EUS with FNA or deep submucosal biopsy was performed in all patients on an outpatient basais by one of two physicians (Attwell A, Fukami N). Review of all subsequent clinic notes and operative reports was performed in order to determine follow-up and final diagnoses.

Results: Between July 2009 and December 2013, 10 patients [3 males, 7 females, median age 52 (26-64) years] underwent EUS for a gastroduodenal SEL and were diagnosed with EP. One patient was symptomatic. Six (60%) lesions were in the antrum, 3 (30%) in the body, and 1 (10%) in the duodenum. A mucosal dimple was noted in 6 (60%). Mean lesion size was 17 (8-25) mm. Gastrointestinal wall involvement: muscularis mucosae, 10%; submucosa, 70%; muscularis propria, 60%; and serosa, 10%. Nine (90%) lesions were hypoechoic and 5 (50%) were homogenous. A duct was seen in 5 (50%). FNA was attempted in 9 (90%) and successful in 8 (80%) patients after 4 (2-6) passes. Cytology showed acini or ducts in 7 of 8 (88%). Superficial biopsies in 7 patients (70%) showed normal gastric mucosa. Deep endoscopic biopsies were taken in 2 patients and diagnostic in one. One patient (10%) developed pancreatitis after EUS-FNA. Two patients (20%) underwent surgery to relieve symptoms or confirm the diagnosis. The main limitation of the study was the fact that it was retrospective and performed at a single medical center.

Conclusion: EUS features of EP include antral location, mucosal dimple, location in layers 3-4, and lesional duct, and FNA or biopsy is accurate and effective.

Keywords: Ectopic pancreas; Endoscopic ultrasound; Endoscopy; Pancreatitis; Subepithelial mass.

Figure 1

Esophagogastroduodenoscopy and endoscopic ultrasound evaluation of gastric ectopic pancreas. A: Esophagogastroduodenoscopy image showing subepithelial lesions (SEL) in the antrum with overlying dimple (arrow); B: Endoscopic ultrasound image showing gastric SEL with intra-lesional duct (arrow).

Figure 2

Endoscopic ultrasound-guided tissue acquisitions for ectopic pancreas. A: Endoscopic ultrasound-fine-needle aspiration (EUS-FNA) of gastric ectopic pancreas (EP) lesion; B: Cell block cytology image showing classic cytologic features of EP including pancreatic acini, magnification × 20; C: Endoscopic deep biopsy of EP lesion.

Figure 3

Exam findings consistent with acute ectopic pancreatitis in a 26 year-old female with recurrent epigastric pain. A: Esophagogastroduodenoscopy image showing subepithelial lesions (SEL) in antrum with overlying erythema and edema; B: Computed tomography scan image showing SEL in antrum of stomach with localized inflammatory reaction (arrow).