Korean J Gastroenterol.  2022 Oct;80(4):195-199. 10.4166/kjg.2022.078.

Ectopic Pancreas with Walled-off Necrosis Mimicking Malignant Submucosal Gastric Tumor

Affiliations
  • 1Departments of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
  • 2Departments of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea

Abstract

An ectopic pancreas rarely transforms into a malignancy, and the symptoms vary from patient to patient. The most commonly observed site of an ectopic pancreas is the antrum of the stomach. A 59-year-old male patient with severe abdominal pain underwent CT. A 9.6 cm-sized well-defined exophytic huge mass with heterogenic density was located between the stomach distal antrum and duodenum. A malignant submucosal tumor was suspected because of the exophytic dirty huge mass. Initially, surgery was considered to confirm the histological evaluation. After 2 months, the abdominal pain disappeared, and the follow-up MRI scan showed a decrease in size, which contained a necrotic component inside. It was confirmed that the parenchymal tissue was the pancreas. The pathology through EUS-guided fine needle aspiration (EUS-FNA) was normal pancreatic acinar cells, smooth muscle fragments, squamous cyst, and some neutrophils (abscess). Walled-off necrosis occurs as a complication of acute pancreatitis with parenchymal tissues and surrounding tissues, but complications of ectopic pancreatitis occurred in this case. Abdominal pain due to ectopic pancreas leading to the formation of a giant abscess has been reported as a very rare case. Diagnosis through biopsy is most important when a malignant submucosal tumor is suspected. In addition, it is important to determine the clinical features, examination findings, such as EUS, CT, and MRI, and the changes according to the follow-up period. This paper reports a case of ectopic pancreas, resulting in necrotic tissue and walled-off necrosis, abdominal pain, and spontaneous improvement.

Keyword

Ectopic pancreas; Gastric submucosal tumor; Walled off necrosis

Figure

  • Fig. 1 Abdominal pelvis computed tomography. (A, B) Necrotic mass-like lesion abutting the stomach distal antrum and duodenum occupying omentum and mesentery was noticed in coronal view. (C) Severe necrosis and abscess changes were observed in the axial view.

  • Fig. 2 (A) Esophagogastroduodenoscopy. The uneven surface without a loss of mucosa was observed on the antrum posterior wall. (B) Endoscopic ultrasonography. A huge hyperechoic lesion was noted.

  • Fig. 3 Pancreas magnetic resonance imaging (pre- & post-contrast)+diffusion. Probable necrotizing pancreatitis with walled-off necrosis arising from ectopic pancreas rather than a malignant condition. (A) High signal intensity was observed in fat-suppressed pre-contrast T1-weighted image. (B) Soft tissue contains microcystic or microductular structure in the T2-weighted image. (C) High signal intensity was observed in the 3 min delayed-coronal view.

  • Fig. 4 (A) A 3×4 cm-sized heterogeneous echogenic mass observed in the antrum. (B) Endoscopic ultrasound-guided fine-needle aspiration. Cytology and biopsy were performed twice with a 19G needle.

  • Fig. 5 Histology examination. (A) normal pancreatic acinar cells. (B) Smooth muscle fragments. (C) Neutrophils (abscess). (D) Squamoid cyst.


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