ELECTRONIC IMAGE OF THE MONTH Bowel Rest Payal Saxena,* Deborah Belchis,‡ and Anne Marie Lennon*,§ *Division of Gastroenterology and Hepatology, Department of Medicine, ‡Department of Pathology, §Department of Surgery, The Johns Hopkins Medical Institutions, Baltimore, Maryland
70-year old man with a 50-year history of Crohn’s disease developed crampy lower abdominal pain, bloating, and a decreased number of bowel movements. Past medical history was remarkable for hypertension and atrial fibrillation. Abdominal examination was unremarkable. Laboratory testing was normal. Computed tomography of the abdomen showed an ileal stricture, 25 cm in length (Figure A). No other abnormalities were detected. Colonoscopy was performed to the terminal ileum where the stricture was identified. Biopsy specimens confirmed Crohn’s ileitis. Endoscopic dilatation could not be performed because of the length of the stricture and the patient was referred for ileocolonic resection. The sections of the resected small intestine showed a Crohn’s-related stricture. Additional incidental findings included a Meckel’s diverticulum containing 3.5-cm of heterotopic pancreas (Figure B), also known as a pancreatic rest, with an intraductal papillary mucinous neoplasia (IPMN) (Figure C, arrow) with high-grade dysplasia (Figure D, arrow). Subsequent abdominal magnetic resonance imaging and magnetic resonance cholangiopancreatography (Figure E)
A
showed multiple pancreatic cysts that communicated with a normal-caliber main pancreatic duct. These features are consistent with a diagnosis of branch-duct IPMN (BDIPMN). Heterotopic pancreas is pancreatic tissue found anywhere along the gastrointestinal tract that lacks an anatomic and vascular connection to the normal pancreas. IPMN arising from heterotopic pancreas is rare, with very few cases reported.1 Furthermore, there have been only 32 reported cases of malignancy arising within the heterotopic pancreatic tissue and the true incidence is unknown.2 IPMNs first were reported in 1982 and are defined as intraductal grossly visible epithelial neoplasms of mucin-producing cells arranged in papillary formations, originating in the main pancreatic ducts or its branches.3 IPMNs can affect the main pancreatic duct (main-duct IPMN), branch ducts (BD-IPMN), or both the main and side branches (mixed-IPMN). Management consists of surveillance, or surgical resection in cysts deemed to be at high risk of malignant Clinical Gastroenterology and Hepatology 2015;13:e173–e174
ELECTRONIC IMAGE OF THE MONTH, continued transformation. Surgical resection is recommended for most patients with main- or mixed-duct IPMN because high-grade or invasive adenocarcinoma is found in between 58% to 63% of patients who undergo surgical resection.3 In contrast, BD-IPMNs are associated with a much lower risk of malignant transformation, with 25% of patients who undergo surgical resection found to have high-grade or invasive carcinoma.3 To determine appropriate management, BD-IPMNs should be characterized in terms of size, presence of enhancing solid component, mural nodule, suspicious cytology, or main duct involvement. Consensus guidelines recommend surgery for symptomatic BDIPMNs, or those with high-risk features.3 Surveillance imaging (computed tomography, magnetic resonance imaging, or endoscopic ultrasound) is recommended for the remainder of BD-IPMNs, with surveillance intervals determined by the size of the cyst.
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References 1.
Tsapralis D, Charalabopoulos A, Karamitopoulou E, et al. Pancreatic intraductal papillary mucinous neoplasm with concomitant heterotopic pancreatic cystic neoplasia of the stomach: a case report and review of the literature. Diagn Pathol 2010;5:4.
2.
Song JY, Han JY, Choi SK, et al. Adenocarcinoma with intraductal papillary mucinous neoplasm arising in jejunal heterotopic pancreas. Korean J Pathol 2012;46:96–100.
3.
Tanaka M, Fernandez-del Castillo C, Adsay V, et al. International consensus guidelines 2012 for the management of IPMN and MCN of the pancreas. Pancreatology 2012;12:183–197.
Conflicts of interest These authors disclose the following: Anne Marie Lennon has received consulting fees from Boston Scientific, and Payal Saxena has received consulting fees from Boston Scientific and research support from Cook Medical. The remaining author discloses no conflicts. Most current article © 2015 by the AGA Institute 1542-3565/$36.00 http://dx.doi.org/10.1016/j.cgh.2015.04.025