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Keywords
Heterotopic pancreas, pancreatitis, gastric cancer.
Introduction
A 30-year-old presented with clinical signs suggesting pancreatitis, but imaging suggested diffuse gastric cancer. Massive infiltration of the stomach by a heterotopic, acutely inflamed pancreas was found at surgery.
Methods for Image Capture/Processing
SVHS tape with digital capture using Dazzle.
Disclaimer
No experimental procedures or devices were used in this report.
Case
A 30-year-old patient with history of binge alcohol drinking presented to a local hospital with pain in the epigastric area, radiated to his back and his flanks, associated with nausea following a bout of heavy alcohol consumption. He had a similar bout of this type of pain one year previously. At presentation, he had moderately elevated amylase at 147 IU,(nl less than 40 IU) and lipase at 667 IU (nl less than 300 IU). He was diagnosed with pancreatitis and was admitted. The day after admission, he developed a fever of 38.5 C. A CT scan was done which was interpreted as a pancreatic phlegmon and he was transferred to a tertiary care facility.
His past medical history is otherwise unremarkable. He was taking no medications.
At the time of transfer, his physical exam was unremarkable other than some epigastric tenderness.
His laboratory results at the time of transfer revealed a persistant low level elevation of lipase and amylase levels, without abnormalities on a liver chemistry profile. His complete blood count was normal.
An ultrasound of the gallbladder was unremarkable.
The outside CT scan was reviewed, and felt to
show a normal pancreas, but there was diffuse thickening of
the wall of much of the stomach and edema of the adjacent
omental fat with some free fluid in the pelvis, raising the
possibility of carcinomatosis (Figure 1A). A correlative Visible
Human image and associated link is shown in Figure 1B.
An upper GI endoscopy revealed diffusely thickened submucosal folds in the distal stomach through the antrum. Biopsy forcep prodding of these folds failed to cause indentation, suggesting that the the folds were quite firm. An EUS examination was performed which showed diffuse thickening of the gastric wall, primarily in echo-layers 3 and 4 (submucosa and muscularis propria), with sonographic disruption of the serosa (Figure 2). No biliary or pancreatic abnormalities were noted, and no accessible free fluid was found. Fine needle aspiration of the submucosal process (Video Clip 1) did not show evidence of malignancy (Figure 3). EUS staging suggested that if this were malignant it would be T3N0 disease. Pinch biopsies were non-diagnostic.
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Figure 2 |
Video Clip 1: Fine needle aspiration of the submucosal process.
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Figure 3 |
A decision was made to proceed to surgery rather than reattempt endoscopic diagnosis, since the managing physicians felt that a biopsy which did not show cancer would have resulted in surgical exploration, whereas a biopsy which did show cancer would also result in laparoscopy/surgical exploration.
The patient was taken to the surgical suite where free fluid was found in the abdomen, without studding of the peritoneal surfaces. Cytology on the free fluid did not show malignant cells. The antrum was palpated and felt to be nodular and thickened. A 7 cm by 2 cm by 1 cm full thickness elliptical biopsy was removed (Figure 4) and sent for frozen section. This revealed ectopic pancreatic tissue. No further resection was performed.
Final histology demonstrated heterotopic pancreatic tissue with hemorrhagic cyst and acute inflammation without atypia, suggesting "pancreatitis of the stomach" (Figure 5-7).
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Figure 5 |
Figure 6 |
Figure 7 |
The patient recovered uneventfully, and has sworn off alcohol.
Discussion
Heterotopic pancreas is an uncommon but not an exceedingly rare finding. Most of the time, the heterotopic pancreas is usually small (1 cm to 3 cm in size) and located in the antrum. Pancreatic rests are often discovered incidentally (1-5).
Larger tumors, or in cases with symptoms, the preoperative diagnosis can be difficult to make. It is a congenital developmental anomaly and is discovered in all age groups, including being listed as a cause of tumors in children (6).
Despite the observation that most cases of heterotopic pancreas do not cause problems, the condition has been reported to lead to symptoms from inflammation (as in our case), obstruction, or even malignant transformation (7-12).
Smaller rests have been removed using endoscopic techniques, primarily to secure a diagnosis, as the smaller tumors are often asymptomatic (13).
Our case appears to be somewhat unique, in that the pancreatic tissue was very extensive, and infiltrated the major part of the distal stomach. The presentation was probably due to alcohol-induced inflammation. In addition to giving the patient symptoms, the inflammation appeared to lead to transmural and extraserosal involvement, simulating a T3 gastric cancer. Fortunately for this patient, a benign, rather than malignant cause was found for his radiologic findings.
Although malignant transformation has been reported, this appears to be uncommon enough that recommendations on follow up probably should be based on symptoms. Hopefully, with the cessation of alcohol use, the patient will not have further episodes of "gastric pancreatitis."
References
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2. Hsia CY, Wu CW, Lui WY. Heterotopic pancreas: a difficult diagnosis. J Clin Gastroenterol. 1999 Mar;28(2):144-7.
3. Park SH, Han JK, Choi BI, Kim M, Kim YI, Yeon KM, Han MC. Heterotopic pancreas of the stomach: CT findings correlated with pathologic findings in six patients. Abdom Imaging. 2000 Mar-Apr;25(2):119-23.
4. Thoeni RF, Gedgaudas RK. Ectopic pancreas: usual and unusual features. Gastrointest Radiol. 1980 Feb 1;5(1):37-42.
5. Monig SP, Selzner M, Raab M, Eidt S. Heterotopic pancreas. A difficult diagnosis. Dig Dis Sci. 1996 Jun;41(6):1238-40.
6. Murphy S, Shaw K, Blanchard H. Report of three gastric tumors in children. J Pediatr Surg. 1994 Sep;29(9):1202-4.
7. Eisenberger CF, Kropp A, Langwieler TE, Gocht A, Izbicki JR, Knoefel WT. Heterotopic pancreatitis: gastric outlet obstruction due to an intramural pseudocyst and hamartoma. Z Gastroenterol. 2002 Apr;40(4):259-62.
8. Burke GW, Binder SC, Barron AM, Dratch PL, Umlas J. Heterotopic pancreas: gastric outlet obstruction secondary to pancreatitis and pancreatic pseudocyst. Am J Gastroenterol. 1989 Jan;84(1):52-5.
9. Huang YC, Chen HM, Jan YY, Huang TL, Chen MF. Ectopic pancreas with gastric outlet obstruction: report of two cases and literature review. Chang Gung Med J. 2002 Jul;25(7):485-90.
10. Brandimarte G, Tursi A. Abdominal pain and hyperamylasaemia due to gastric pancreatic heterotopia: endoscopic diagnosis and treatment. Endoscopy. 2000 Feb;32(2):S10.
11.Herold G, Kraft K. Adenocarcinoma arising from ectopic gastric pancreas: two case reports with a review of the literature. Z Gastroenterol. 1995 May;33(5):260-4.
12. Osanai M, Miyokawa N, Tamaki T, Yonekawa M, Kawamura A, Sawada N. Adenocarcinoma arising in gastric heterotopic pancreas: clinicopathological and immunohistochemical study with genetic analysis of a case. Pathol Int. 2001 Jul;51(7):549-54.
13. Faigel DO, Gopal D, Weeks DA, Corless C. Cap-assisted endoscopic submucosal resection of a pancreatic rest. Gastrointest Endosc. 2001 Dec;54(6):782-4.
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