Adenocarcinoma arising from jejunal ectopic pancreas mimicking peritoneal metastasis from colon cancer: a case report and literature review

Abstract

Adenocarcinoma arising from jejunal ectopic pancreas is very rare. We report a case of a 69-year-old female with adenocarcinoma arising from jejunal ectopic pancreas after resection of advanced colon cancer. She underwent right hemicolectomy for advanced ascending colon cancer (ypT3N0M0, stage IIA) after chemotherapy. Two and half years after colectomy, her tumor markers were elevated, and computed tomography revealed a mass measuring 20 × 20 mm in the small intestine, having an abnormal uptake of 18F-fluorodeoxyglucose on 18F-fluorodeoxyglucose-positron emission tomography (18FDG-PET). Double-balloon enteroscopy revealed a submucosal tumor in the jejunum, and histopathology of biopsy specimens from that lesion showed ectopic pancreas without malignancy. Therefore, peritoneal metastasis from colon cancer concomitant with ectopic pancreas or adenocarcinoma arising from ectopic pancreas was considered as a differential diagnosis. She underwent laparoscopic jejunectomy. Pathological examination revealed a moderately differentiated adenocarcinoma arising from jejunal ectopic pancreas, not peritoneal metastasis from colon cancer. Even if histopathology of the biopsy specimen shows ectopic pancreas without malignancy, adenocarcinoma arising from ectopic pancreas should be considered when the tumor markers are elevated or the lesion has an abnormal uptake of 18FDG.

The role of endoscopy in subepithelial lesions of the GI tract

“…66,67 Malignant transformation also has been reported. [68][69][70] A firm SEL with central umbilication along the greater curve of the distal stomach is considered diagnostic for a pancreatic rest, and therefore EUS is not required. However, differentiation of a pancreatic rest from other gastric SELs, such as a GI stromal tumor or carcinoid tumor may be difficult when these features are not present.…”

Resistant starch prevents tumorigenesis of dimethylhydrazine-induced colon tumors via regulation of an ER stress-mediated mitochondrial apoptosis pathway

“…Colon cancer is one of the most common gastrointestinal tumors, with highly invasive ability characterized by rapid invasion of lymphatics, flow transfer and local invasion ( 29 , 30 ). Various studies have indicated that most cases of sporadic colon cancer can be attributed to diet ( 31 , 32 ).…”

Intestinal Heterotopic Pancreas Involved by Simultaneous PanIN-2 Lesion and Endocrine Microadenoma: a Unique Case

“…Heterotopic pancreas represents a rare finding in the intestinal wall, being observed in 0.5% of upper abdominal laparotomies and in 0.6-13% of necropsy studies [2,9]. Usually it is discovered in the upper gastrointestinal tract, the stomach, duodenum and jejunum being the most common location [2,[9][10][11]. Frequently, HP is misdiagnosed as a submucosal primary tumor, usually mesenchymal type, polyps or metastatic tumor as this case was.…”

“…The large majority of the neoplasms have ductal differentiation including intraepithelial or infiltrative, cystic or solid type lesions. Malignant ductal lesions and their precursors are rarely seen in HP [2,3].…”