DSU722_UMBRUCH.inddCase Reports
repeated hepatic encephalopathy due to an IPVS forming a pe- ripheral portal aneurysm which was successfully treated with a new surgical shunt closure.
Case Report
A 70-year-old woman was referred to our hospital because of repeated hepatic encephalopathy due to hyperammonemia. She underwent hemodialysis for chronic renal failure in 2004. At that time, she was diagnosed as having hyperammonemia, and was treated with oral medicine (lactulose). However, she repeatedly suffered from hepatic encephalopathy due to hyperammonemia over a period of 4 months. On admission, the physical examina- tion was unremarkable. Admission laboratory tests revealed an elevated serum ammonium level (314 l/dl), mildly decreased se- rum albumin (3.3 g/dl), mild anemia (hemoglobin 10.3 g/dl), and mild thrombocytopenia (12.9 ! 10 4 l). The indocyanine green retention rate at 15 min was 30%. With regard to virus markers, both hepatitis B surface antigen and hepatitis C antibody were negative. She had a history of aortic arch replacement for aortic aneurysm, but no history of trauma or liver disease.
Ultrasonography and color Doppler ultrasonography revealed a portal aneurysm, 4 cm in diameter, connecting the dilated pos- terior branch of the portal vein to the dilated short hepatic vein in the right lobe ( fig. 1 ). Computed tomography showed the portal aneurysm from the dilated posterior branch of the portal vein (1.5 cm throughout its length) to the dilated short hepatic vein (1.2 cm throughout its length; fig. 2 , 3 ). No other intrahepatic shunt or extrahepatic shunt was revealed. The serum ammonia levels in the portal vein and the right hepatic vein were 296 and 54 l/dl, respectively. The ammonia exclusion ratio of the liver was 82%. At laparotomy, the liver was normal, and no ascites was found. The portal aneurysm and dilated short hepatic vein were seen in the surface of the right lobe. While performing the Prin- gle maneuver and clamping the inferior vena cava (IVC) below the liver, the wall of the portal aneurysm was opened, and the site of inflow from the portal vein and the site of outflow to the short hepatic vein were closed with interrupted sutures for 6 min ( fig. 4 ). Pressure in the portal vein changed from 8 mm Hg before shunt closure to 9 mm Hg after shunt closure. The total operation time was 156 min, and the total blood loss was 234 ml. The serum am- monia level had normalized by the next day. The patient’s postop- erative course was uneventful, and she was discharged 12 days after surgery. 12 months after surgery, she had no recurrence of hyperammonemia or hepatic encephalopathy.
Key Words Portosystemic venous shunt Portal aneurysm Shunt closure
Abstract Background/Aims: A surgical shunt closure via the lumen of an
intrahepatic portal aneurysm was successfully performed in a 70- year-old Japanese woman with hepatic encephalopathy due to hy- perammonemia. She had a 4-month history of repeated hepatic en- cephalopathy which persisted after treatment with oral medicine. Color Doppler ultrasonography and computed tomography revealed a cystic peripheral portal aneurysm, 4 cm in diameter, connecting the posterior branch of the portal vein to the short hepatic vein in the right lobe. Methods: While performing the Pringle maneuver and clamping the inferior vena cava below the liver, the wall of the portal aneurysm was opened, and the site of inflow from the portal vein and the site of outflow to the hepatic vein via the lumen of the portal an- eurysm were closed with interrupted sutures. Results: The patient’s postoperative course was uneventful, and she was discharged 12 days after surgery. 12 months after surgery, she had no recurrence of hyperammonemia or hepatic encephalopathy. Conclusion: Surgical shunt closure via the lumen of a portal aneurysm can be performed safely, easily, and completely with good vision.
Copyright © 2006 S. Karger AG, Basel
Introduction
Repeated hepatic encephalopathy due to hyperammonemia is sometimes refractory with oral drugs. Surgical ligation, hepatec- tomy, and non-surgical treatment with interventional radiology (IVR) have been reported to be effective for intrahepatic porto- systemic venous shunt (IPVS) with repeated hepatic encephalop- athy [1–8] . Numerous variations between the portal vein and the hepatic vein in IPVS have been reported [9] , but there are no stan- dard therapeutic methods. Herein we report on a patient with
Published online: October 10, 2006
© 2006 S. Karger AG, Basel
Accessible online at: www.karger.com/dsu
Dig Surg 2006;23:259–261 DOI: 10.1159/000096157
Surgical Shunt Closure via the Lumen of an Intrahepatic Portal Aneurysm
S. Ariizumi, K. Takasaki, M. Yamamoto, H. Katsuragawa, S. Katagiri, K. Yoshitoshi, Y. Kotera
Department of Surgery, Tokyo Women’s Medical University, Tokyo , Japan
Case Reports 260
Discussion
IPVS is a relatively rare entity, but numerous variations be- tween the portal vein and hepatic vein have been reported [9] . There have been only four previous reports of patients who un- derwent hepatectomy or portal vein ligation for a peripheral por- tal aneurysm [2–5] . We performed surgical shunt closure with interrupted sutures via the lumen of the peripheral portal aneu- rysm. We have not been able to find previous reports in the Eng- lish or Japanese literature of surgical shunt closure via the lumen of a portal aneurysm. The method consisted of simple and com- plete closure of the shunt, and successfully preserved the liver parenchyma and liver function. We therefore present this method as a useful surgical treatment for portal aneurysm.
Recently, shunt closure with IVR for IPVS has been attempted. There have been two previous reports of patients with a portal aneurysm which was successfully obliterated with microcoils via the retrograde transvenous route [7, 8] . However, numerous mi- crocoils were required to obliterate even a small portal aneurysm, and not only microcoils but also sclerosing agents were required to achieve complete obliteration [7] . Cost is an issue because nu- merous microcoils may be required to obliterate a larger portal aneurysm. Several complications associated with the use of scle- rosing agents, such as hematuria, portal vein thrombosis, and adult respiratory distress syndrome, are also known. We per- formed surgical treatment because the patient had a large portal aneurysm, and dislocation of microcoils or the sclerosing agent to the IVC was a concern in the case of treatment with IVR.
The postoperative course of most previous patients has been reported as uneventful. However, an increase in pressure of the portal vein after shunt closure is known to be a critical complica- tion even in patients without cirrhosis [6] . It is important to select a therapeutic method that will not result in elevated pressure of the portal vein after shunt closure. In our patient, almost no change in pressure of the portal vein was measured before and after shunt closure.
Otsubo et al. [10] reported that the ammonia exclusion ratio of the liver was a useful method for determining closure of a por- tosystemic shunt because it allows preoperative estimation of changes in the serum ammonia level. We decided to perform shunt closure because amelioration of hyperammonemia was ex- pected based on the ammonia exclusion ratio. Neither hyperam-
monemia nor hepatic encephalopathy recurred after shunt clo- sure.
The Pringle maneuver and clamping the IVC below the liver are known to be useful methods for controlling operative blood loss during hepatectomy. We were able to control blood loss while closing the shunt via the lumen while performing the Pringle ma- neuver and clamping the IVC below the liver.
Conclusion
Surgical shunt closure via the lumen of a portal aneurysm can be performed safely, easily, and completely with good vision.
Acknowledgement
The authors are indebted to Assoc. Prof. Raoul Breugelmans of the International Medical Communications Center of Tokyo Medical University for reviewing the manuscript.
References
1 Raskin NH, Price JB, Fishman RA: Portal-systemic encephalopathy due to congenital intrahepatic shunts. N Engl J Med 1964; 270: 225– 229.
2 Chagnon SF, Vallee CA, Barge J, Chevalier LJ, Gal JL, Blery MV: Aneu- rysmal portohepatic venous fistula: report of two cases. Radiology 1986; 159: 693–695.
3 Ubakata H, Tabuchi T, Matsumoto F, Taira T, Funayama H, Yumoto J, Sato S, et al: A surgical case of intrahepatic porto-venous shunt with portal systematic encephalopathy (in Japanese). J Jpn Clin Surg 1991;
52: 2965–2970. 4 Morita Y, Hasegawa T, Saito H, Sato Y, Uchino J, Konno N: Intrahe-
patic portal venous fistula; report of a resected case (in Japanese). Jpn J Med Imag 1991; 11: 710–715.
5 Miura A, Iida M, Chiba T, Sekita Y, Hotta M, Yamazaki S: A case of successful surgical treatment for intrahepatic portal-left hepatic ve- nous shunt (in Japanese). J Jpn Clin Surg 2003; 64: 2248–2251.
6 Nakatsuji Y, Kiyosawa K, Furuta K, Nakano Y, Suyama K, Sasaki Y, Yoshizawa K, et al: A case of hepatic encephalopathy and pulmonary hypertension due to intrahepatic portacaval shunt (in Japanese). Acta Hepatol Jpn 1991; 32: 197–204.
7 Nakashige A, Ichiki T, Maeoki T, Fujiyama M, Ito M: Effective embo- lization for intrahepatic venous shunt; a case report (in Japanese). Jpn J Clin Radiol 1995; 40: 729–732.
8 Hiraoka A, Kurose K, Hamada M, Azemoto N, Tokumoto Y, Hirooka M, Hasebe A, et al: Hepatic encephalopathy due to intrahepatic porto- systemic venous shunt successfully treated by interventional radiology. Intern Med 2005; 44: 212–216.
9 Park JH, Cha SH, Han JK, Han MC: Intrahepatic portosystemic venous shunt. AJR 1990; 155: 527–528.
10 Otsubo T, Takasaki K, Tsugita T, Yamamoto M, Suzuki T, Miyazaki S, Nakagami T: Intrahepatic shunt evaluated by serum ammonia level: closing of porto-systemic shunt (in Japanese). Jpn J Gastroenterol Surg 1996; 29: 2265–2270.
Shun-ichi Ariizumi, MD Department of Surgery, Tokyo Women’s Medical University 8-1 Kawada, Shinjuku-ku Tokyo, 162-8666 (Japan) Tel. +81 3 3353 8111, Fax +81 3 5269 7435 E-Mail ari@gd6.so-net.ne.jp
Fig. 1. Ultrasonography ( a ) and color Doppler ultrasonography ( b ) reveal a portal aneurysm connecting the dilated posterior branch of the portal vein to the dilated short hepatic vein in the right lobe. Fig. 2. Computed tomography shows a portal aneurysm, 4 cm in diameter, from the dilated posterior branch of the portal vein to the dilated short hepatic vein. Fig. 3. 3D-computed tomography showing a portal aneurysm. Fig. 4. The wall of the portal aneurysm is opened. The site of in- flow from the portal vein (arrow) and the site of outflow to the short hepatic vein (arrow heads) are identified ( a ) and closed with interrupted sutures ( b ).
Case Reports 262
weight loss. Laboratory data included normal hematocrit and WBC, but elevated serum amylase 806 U/l (normal 20–120 U/l), lipase 1,229 U/l (normal 8–57 U/l), -GT 751 U/l (normal 7– 50 U/l), ALT 195 U/l (normal 10–60 U/l), APT 103 U/l (normal 5–40 U/l), total bilirubin 10.6 mg/dl (normal 0.4–2 mg/dl), direct bilirubin 8.54 mg/dl (normal 0–0.4 mg/dl), and LDH 291 U/l (normal 98–192 U/l). Tumor markers of CA 19-9 was 209.69 U/l (normal 0–37 U/l), CEA was 4.93 ng/ml (normal ! 5 ng/ml), and AFP was 1.7 ng/ml (normal ! 20 ng/ml). Chest and abdomen X- rays were unremarkable. Abdominal sonography showed a dilat- ed common bile duct (2.0 cm) and dilated intrahepatic ducts. Ab- dominal computerized tomography (CT) revealed a dilated com-
Key Words Ectopic pancreas Ampulla of Vater Periampullary tumor Total ampullectomy Sphincterotomy
Abstract Ectopic pancreas is an uncommon condition and is usually found
in the gastrointestinal tract, such as stomach, duodenum and jeju- num. However, ectopic pancreas in the ampulla of Vater is rare and its clinical presentations may be similar to periampullary cancer. It is difficult to diagnose preoperatively. We present such a case where the diagnosis was proven postoperatively. Our patient, a 51-year-old man, presented with epigastric pain, jaundice, weight loss and ab- normal laboratory data. Imaging study, including abdominal sonog- raphy, abdominal computerized tomography with contrast and en- doscopic retrograde cholangiopancreatography, showed a mass protruding into the ampulla of Vater. The mass was resected and his- tological examination revealed an ectopic pancreas. The patient pre- sented with symptoms of periampullary tumor but the imaging study did not reveal an obvious lesion for us consider the possibility of ectopic pancreas. Surgical excision is indicated for symptomatic cases. Copyright © 2006 S. Karger AG, Basel
Introduction
Ectopic pancreas is defined as pancreatic tissue that lacks di- rect or vascular connection to normal pancreas [1] . Ectopic pan- creas is an uncommon condition. In 70% of the cases it is found in the stomach, duodenum and jejunum [2] . We present a case of ectopic pancreas in the ampulla of Vater (AoV). Only several such cases have been reported in the literature [3–9] . The common presenting symptoms include epigastric pain and jaundice [2] . Our case also had weight loss and abnormal laboratory data, which were not seen in previous reports.
Case Report
A 51-year-old man presented with epigastric pain for almost 1 year. The pain was dull, intermittent and non-referring. He had a weight loss of 5 kg within 4 months. He consulted a local hospi- tal and was treated for gastritis. Physical examination on admis- sion showed epigastric tenderness, gross jaundice and recent
Dig Surg 2006;23:262–264 DOI: 10.1159/000096158
Ectopic Pancreas in the Ampulla of Vater with Obstructive Jaundice
A Case Report and Review of Literature
Shao-Jiun Chou a, b , Yu-Wei Chou
a , Hsiang-Chun Jan a, b ,
Victor T.K. Chen a, b , Tzu-Hung Chen
a, b
a Division of General Surgery, Department of Surgery, Cardinal
Tien Hospital, College of Medicine, Fu Jen Catholic University, and b
Tri-Service General Hospital and National Defense Medical Center, Taipei , Taiwan/ROC
Fig. 1. Marked dilatation of intrahepatic biliary ducts (arrow). Fig. 2. The CBD was dilated in the ampullary region (arrow) and the pancreas was swollen.
1
2
Case Reports 263
mon bile duct extending down to the ampullary region ( fig. 1, 2 ). Endoscopic retrograde cholangiopancreatography (ERCP) showed a dilated common bile duct and a mass protruding into the AoV ( fig. 3, 4 ). A biopsy was done and revealed chronic in- flammation. The Whipple procedure was performed due to the suspicion of tumor of AoV. The resected specimen of ampulla showed gross hypertrophy without the mass ( fig. 5 ). Histological evaluation revealed a mixture of pancreatic acini and ducts ( fig. 6 ). The postoperative course was smooth and the patient was discharged on postoperative day 10. During the postoperative fol- low-up his symptoms were relieved and laboratory data returned to a normal range.
Fig. 3. ERCP showed a protruding mass at the AoV. Fig. 4. Distal CBD showed marked narrowing with near total ob- struction.
Fig. 5. AoV showed gross hypertrophy without the mass. Fig. 6. Histopathological sections showed pancreatic acini and ducts.
Discussion
The diagnosis of ectopic pancreas is easy if it shows the typical landmark of ‘central dimpling’. However, in our case, such a char- acteristic sign was not seen. The ectopic pancreatic tissue may be too small and difficult to see near the orifice of the AoV.
Ectopic pancreas is usually asymptomatic, but it is capable of producing clinical symptoms, depending on its location and size [10] . In reviewed reports, the most common sites include stom- ach, duodenum, and jejunum, which account for about 70% of cases [2] . Only a few cases have been reported in the AoV. The sizes reported range from 2.0 to 25 mm [3–9] . The most common
5
Case Reports 264
presenting symptoms were abdominal pain (45.5%) and epigas- tric discomfort (12.0%). In our case, ectopic pancreas located in AoV presented with epigastric pain, gross jaundice and weight loss. The symptoms of ectopic pancreas in the AoV are similar to those of periampullary cancer. It is very difficult to differentiate them based on clinical symptoms alone.
Useful imaging study of the periampullary region includes ab- domen sonography, endoscopic ultrasonography (EUS), abdo- men CT, magnetic resonance imaging (MRI), and ERCP. Abdom- inal sonography may not provide much information in such pa- tients, as in our case, because the ectopic pancreatic tissue is small and located in the submucosal layer of AoV [11] . In EUS the ecto- pic pancreas in the gastrointestinal tract appears hypoechoic or has mixed echogenic lesions in the submucosa [12] . EUS features of ectopic pancreas in AoV have not been reported. Abdominal CT can evaluate the internal organs near to the periampullary region and rule out any periampullary abnormality. ERCP with biopsy is the most important tool in such cases. Ectopic pancre- atic tissue may show the ‘central dimpling’ in ERCP if the tissue is large enough. Endoscopic sphincterotomy may supply larger specimens for diagnosis, however it has more complications, such as hemorrhage, perforation, or pancreatitis.
Hayes-Jordan et al. [13] pointed out ectopic pancreas is associ- ated with muscle hypertrophy. Gaspar Fuentes et al. [14] divided ectopic pancreas into four types: type I composed of all cell types (total heterotopia); type II composed of ducts only (canalicular heterotopia); type III composed of acinar cells only (exocrine het- erotopia), and type IV composed of islets of Langerhans only (en- docrine heterotopia). However, in our case, histological findings revealed a mixture of acini and ducts.
The management of ectopic pancreas depends on the presence of symptoms or not. If the patient is asymptomatic, conservative treatment with regular follow-up is recommended. If the patient is symptomatic, as our case, surgical management is indicated. The size and location of ectopic pancreatic tissue determine what kind of procedure should be performed. Tanaka et al. [15] recom- mended resection of the pancreatic tissue-bearing area, while Jo- chimen et al. [16] recommended surgical excision of ectopic pan- creas if symptoms persisted after supportive treatment failed. If we can localize the ectopic pancreatic tissue preoperatively by im- aging study, limited excision is needed. If ectopic pancreatic tissue is not well circumstanced, wide excision is recommended, such as total ampullectomy. However, wide excision may be technically difficult. We suggest biopsy and sphincterotomy to identify the anatomy and histology first, and then excise the area as much as possible without damaging the common bile duct and pancreatic duct.
Acknowledgement
We thank Miin-Fu Chen, MD, President of the Taiwan Surgi- cal Association, for his help in revising the manuscript.
References
1 Barbosa JJ de C, Dockerty MB, Waugh JM: Pancreatic heterotopia: re- view of the literature and report of 41 authenticated surgical cases of which 25 were clinically significant. Surg Gynecol Obstet 1946; 82: 527– 542.
2 Kaneda M, Yano T, Yamamoto T, Suzuki T, Fugimori K, Itoh H, Mizu- moto R: Ectopic pancreas in the stomach presenting as an inflamma- tory abdominal mass. Am J Gastroenterol 1989; 84: 663–666.
3 Chen CH, Yang CC, Yeh YH, Chou DA, Kuo CL: Ectopic pancreas lo- cated in the major duodenal papilla: case report and review. Gastroin- test Endosc 2001; 53: 121–123.
4 Hoelzer H: An occlusion of Vater’s ampulla by accessory pancreas. Zentralbl Chir 1940; 67: 1715–1717.
5 Varay A: Microscopic epithelioma of Vater’s ampulla. Paris Méd 1946;
1: 183–186. 6 Pearson S: Aberrant pancreas. Review of the literature and report of
three cases, one of which produced common and pancreatic duct ob- struction. Arch Surg 1951; 63: 168–184.
7 Weber CM, Zito PF, Becker SM: Heterotopic pancreas: an unusual cause of obstruction of the common bile duct. Am J Gastroenterol 1968;
49: 153–159. 8 Laughlin EH, Keown ME, Jackson JE: Heterotopic pancreas obstruct-
ing the ampulla of Vater. Arch Surg 1983; 118: 979–980. 9 Kubota K, Bandai Y, Watanabe M, et al: Biliary stricture due to muco-
sal hyperplasia of the common bile duct: a case report. Hepatogastro- enterology 1996; 43: 14.
10 Armstrong CP, King PM, Dixon JM, Macleod IB: The clinical signifi- cance of heterotopic pancreas in the gastrointestinal tract. Br J Surg 1981; 68: 384–387.
11 Dolan RV, Remine WH, Dockerty MB: The fate of heterotopic pancre- atic tissue: a study of 212 cases. Arch Surg 1974; 109: 762–765.
12 Matsushita M, Hajiro K, Okazaki K, Takakuwa H: Gastric aberrant pancreas: EUS analysis in comparison with the histology. Gastrointest Endosc 1999; 49: 493–497.
13 Hayes-Jordan A, Idowu O, Cohen R: Ectopic pancreas as the cause of gastric outlet obstruction in a newborn. Pediatr Radiol 1998; 28: 868– 870.
14 Gaspar Fuentes A, Campos Tarrech JM, Fernandez Burgui J: Ectopias pancreaticas. Rev Esp Enferm Apar Dig 1973; 39: 255–268.
15 Tanaka K, Tsunoda T, Eto T, Yamada M, Jajima Y, Shimogama H, et al: Diagnosis and management of heterotopic pancreas. Int Surg 1993; 78:
32–35. 16 Jochimsen PR, Shirazi SS, Lewis JW: Symptomatic ectopic pancreas
relieved by surgical excision. Surg Gynecol Obstet 1981; 153: 49–52.
Tzu-Hung Chen, MD Division of General Surgery, Department of Surgery Cardinal Tien Hospital 362, Chung Cheng Rd. Hsintien Taipei Hsien 23137 (Taiwan/ROC) Tel. +886 2 2219 3391 66711, Fax +886 2 8665 9727 E-Mail surgery6711@sina.com.tw
Case Reports 265
Abstract Background: Digestive tract schwannomas (DTS) are rare benign
mesenchymal tumours usually affecting females between 30 and 60 years old. Methods: We retrospectively reviewed 2 cases of DTS treated at our hospital. The first case is a 38-year-old female with gas- tric schwannoma presenting with acute upper gastro-intestinal bleeding. The second case is a 36-year-old female with mesenteric schwannoma presenting with chronic right iliac fossa pain. Both pa- tients underwent surgical resection of the tumour. Results: Histolo- gy and immunohistochemistry revealed the typical appearance of a DTS. Conclusion: DTS is most commonly found in the stomach. It is usually asymptomatic but can present with variable symptoms. De- finitive diagnosis can only be made on the basis of immunohisto- chemistry. Surgical resection is the treatment of choice.
Copyright © 2006 S. Karger AG, Basel
Introduction
We report 2 cases of digestive tract schwannomas (DTS), af- fecting different parts of the gastro-intestinal tract. Although be- nign, these rare tumours present with varying signs and symp- toms which can be life threatening. Imaging may be useful in
Dig Surg 2006;23:265–269 DOI: 10.1159/000096159
Digestive Tract Schwannoma
A.A. Khan, A.M.P. Schizas, A.B. Cresswell, M.K. Khan, H.T. Khawaja
Department of General Surgery, Queen Mary’s Hospital Sidcup, Sidcup , UK
identifying such lesions. The definitive diagnosis is only made on histopathological specimens. Complete excision is the treatment of choice, and to date no recurrences have been reported after this.
Case Reports
Case 1: Gastric Schwannoma A 38-year-old female acutely presented with signs and symp-
toms of upper gastro-intestinal bleeding. There was no previous history of indigestion or peptic ulcer disease. She was a non- smoker and drank 10 units of alcohol per week. She was haemo- dynamically stable and had mild epigastric tenderness. Gastros- copy showed a bleeding polypoid tumour in the gastric antrum ( fig. 1 ). Haemostasis was achieved with sclerotherapy, and there- after the patient was commenced on proton pump inhibitors. An abdominal computed tomography (CT) scan confirmed the gas- tric origin, with no adjacent spread ( fig. 2 ). Following multidisci- plinary discussion, the patient underwent elective laparotomy and wedge resection of the tumour. Pathology showed typical ap- pearance of a DTS ( fig. 3 ). The patient remained asymptomatic at 1-year follow-up.
Case 2: Mesenteric Schwannoma A 36-year-old female presented with chronic right iliac fossa
pain which started after right lower rib cage injury 6 months ago. This was described as a muscle spasm with associated nausea, fa- tigue, and weight loss. There were no bowel or urinary tract symp- toms, and the physical examination was unremarkable. An ab- dominal CT scan showed a well-defined lesion between left kid- ney and tail of the pancreas. Magnetic resonance imaging identified mesenteric origin ( fig. 4 ). The patient underwent elec- tive laparotomy, and the tumour was found to originate from the mesentery of the distal transverse colon. Complete resection of the tumour was performed, and pathology confirmed a DTS ( fig. 5 ). The patient still complained of isolated right iliac fossa pain at 1-year follow-up.
Fig. 1. Gastroscopy. a Polypoid tumour at the gastric antrum with prominent bleed- ing. b After sclerosant injection (15 ml of 1: 10,000 adrenaline).
Case Reports 266
Discussion
DTS are rare tumours which belong to the family of gastro- intestinal mesenchymal tumours ( fig. 6 ). These occur most com- monly in females between 30 and 60 years of age. DTS are most likely to arise from Schwann cells of the neural plexus within the digestive wall [1, 2] and can, therefore, occur in any part of the gastro-intestinal tract. The most common site is the stomach (0.2% of all gastric tumours) [1, 3, 4], and only 3% occur in the retroperitoneum [5] .
A gastric schwannoma commonly presents with upper gastro- intestinal bleeding. This is due to erosion of the overlying gastric mucosa which becomes sensitive to gastric acidity [3] . Therefore, proton pump inhibitors may be of benefit in controlling recurrent bleeding prior to definitive treatment. Other DTS rarely cause symptoms and are usually found incidentally during investiga- tion for other problems.
Cross-sectional imaging, such as CT, magnetic resonance im- aging, and transabdominal ultrasonography, may be useful in the detection and characterization of the tumour and its relation- ship with surrounding organs [4, 5] . Definitive diagnosis re- quires histological examination and, more importantly, immu- nohistochemical studies of the resected specimen. The differen- tial diagnosis includes subtypes of gastro-intestinal stromal tumours ( fig. 6 ), especially gastro-intestinal autonomic tumours which, in particular, also arise from the autonomic plexus of the gastro-intestinal tract and have a high risk of malignant behav- iour [1] . On immunohistochemical studies, there is always ex- pression of protein S-100 and glial fibrillary acidic protein [2] . These tumours may express CD34, but not smooth muscle actin or desmin [1, 6] . The KIT protein (CD117), which has been re- cently shown to play major role in the pathogenesis of gastro- intestinal stromal tumours, is also not expressed by true schwan- nomas [6] .
Surgical resection is the treatment of choice, and long-term follow-up of these patients has not shown any propensity to recur- rence following complete excision.
In conclusion, DTS are rare mesenchymal tumours, but they should always be considered in patients with unusual abdominal symptoms or gastro-intestinal bleeding. The stomach is the most common site to be affected, resulting in upper gastro-intestinal bleeding due to mucosal erosion. This can usually be controlled endoscopically, and there appears to be a role for treatment with proton pump inhibitors to reduce the likelihood of re-bleeding. The definitive diagnosis can only be made on the basis of histol- ogy and immunohistochemistry. DTS are differentiated from gastro-intestinal stromal tumours by the absence of KIT protein. Follow-up suggests that complete resection represents an effective long-term treatment modality.
Fig. 2. CT of the abdomen. A 4 ! 2.5-cm soft-tissue mass arising from the lesser curve of the stomach (arrowhead). There is a cen- tral area of necrosis and no invasion of surrounding organs.
Fig. 3. Histopathology and immunohistochemistry, showing the typical appearance of a gastric schwannoma. a HE. ! 25. b HE. ! 40. The sections show a spindle cell tumour arranged in inter- lacing bundles and fascicles. There is focal palisading by tumour cells with formation of extracellular collagen matrix. The spindle cell neoplasm is well demarcated with nuclear pleomorphism and infrequent mitotic figures. Occasional structures resembling Verocay bodies are present, and the lesion is surrounded by a well- defined lymphoid cuff, including occasional germinal centres. c S100 immunostaining. There is strong and widespread positiv- ity for S100 protein, confirming a gastric schwannoma. d CD117 (KIT) Immunostaining. This is completely negative, differentiat- ing such tumours from gastro-intestinal stromal tumours. Fig. 4. Magnetic resonance imaging of the abdomen. There is a well-defined 4.5 ! 4-cm lesion on the left side of the abdomen (arrowheads), anterior to the left kidney and adjacent to the tail of the pancreas. a T 1 -weighted sagittal plane: low signal intensity. b T 2 -weighted sagittal plane: high signal intensity with heteroge- neous appearance and areas of central solidity.
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Fig. 5. Histopathology and immunohistochemistry, showing the typical appearance of a schwannoma. a HE. ! 10. b HE. ! 25. There are interlacing bundles of spindle cells. The stroma con- tains dilated blood vessels and shows oedema. c S100 immuno- staining. The tumour cells are strongly positive for S-100, con- firming the schwannoma. d CD117 immunostaining. The tu- mour cells are negative for CD117 (KIT protein), differentiating such tumours from gastro-intestinal stromal tumours. Fig. 6. Suggested classification of gastro-intestinal mesenchymal tumours [1, 6] . This is a simplified classification on the basis of histological, immunohistochemical, and ultrastructural fea- tures.
5
6
References 1 Prevot S, Bienvenu L, Vaillant JC, de Saint-Maur PP: Benign schwanno-
ma of the digestive tract: a clinicopathologic and immunohistochemi- cal study of five cases, including a case of esophageal tumor. Am J Surg Pathol 1999; 23: 431–436.
2 Jessen KR, Mirsky R: Glial cells in the enteric nervous system contain glial fibrillary acidic protein. Nature 1980; 286: 736–737.
3 Lin CS, Hsu HS, Tsai CH, Li WY, Huang MH: Gastric schwannoma. J Chin Med Assoc 2004; 67: 583–586.
4 Fujii Y, Taniguchi N, Hosoya Y, Yoshizawa K, Yasuda Y, Nagai H, Itoh K: Gastric schwannoma sonographic findings. J Ultrasound Med 2004;
23: 1527–1530.
Aftab A. Khan, MD, MRCS 41 Dorney Rise Orpington BR5 2JG (UK) Tel. +44 1689 83 7979, Mobile +44 7961 88 5883 E-Mail iftee@hotmail.com
5 Ramboer K, Moons P, De Breuck Y, Van Hoe L, Baert AL: Benign mes- enteric schwannoma: MRI findings. J Belge Radiol 1998; 81: 3–4.