Coexistence of annular pancreas with carcinoma in the ... - Springer Link

Abdominal Imaging

© Springer Science⫹Business Media, Inc., 2004 Received: 9 December 2003 / Accepted: 21 January 2004 / Published online: 8 June 2004

Abdom Imaging (2004) 29:703–706 DOI: 10.1007/s00261-004-0178-3

Coexistence of annular pancreas with carcinoma in the dorsal part of pancreas divisum: diagnostic value of magnetic resonance cholangiopancreatography F. Cholet,1 K. Bideau,1 M. Nonent,2 J.-B. Nousbaum,1 H. Goue´rou,1 M. Robaszkiewicz1 1 2

Service d’He´pato-Gastroente´rologie, CHU La Cavale Blanche, Boulevard Tanguy Prigent, 29200, Brest, France Service d’imagerie me´dicale, CHU La Cavale Blanche, Boulevard Tanguy Prigent, 29200, Brest, France

Abstract We report on the incidental observation of a pancreas divisum coexistent with an annular pancreas in a 88-year-old woman presenting with jaundice due to a pancreatic carcinoma. This case report discusses the embryologic hypotheses underlying this peculiar association, highlights the capacities of imaging techniques to depict them, and enhances the performance of magnetic resonance imaging. Key words: Annular pancreas—Pancreas divisum—Pancreas neoplasm—Endoscopic retrograde cholangiopancreatography—Magnetic resonance cholangiopancreatography Annular pancreas (AP) is a rare congenital variant of pancreatic ducts, with an incidence of three in 20,000 autopsies [1]. Its association with a pancreas divisum (PD) has been reported [2– 6]. We describe the coexistence of AP and PD with a pancreatic carcinoma in the same patient; to our knowledge, only one case has been reported in the literature [7].

Case report An 88-year-old woman, with no notable medical history, was admitted for jaundice with neither fever nor pain but accompanied by weight loss of 6 kg. Clinical examination showed excoriated skin from pruritus related to jaundice and a large and palpable gallbladder. The hemogram showed neither anemia nor hyperleukocytosis. Sedimentation rate was increased to 50 mm by the first hour. Total and conjugated bilirubin levels were 192 and 163 ␮mol/L, respecCorrespondence to: F. Cholet; email: [email protected]

tively. Alkaline phosphatase activity was fourfold above normal, and gamma-glutamyl transpeptidase was elevated 30 times the upper limit of normal. Aminotransferase activity in serum and amylase levels were within normal limits. The serum level of the cancer marker CA-19.9 was 554 KU/L (normal ⬍ 37 KU/L). Ultrasonography of the abdomen showed dilatation of the intra- and extrahepatic bile ducts and of the gallbladder. The common bile duct (measuring 13 mm at the hilar level) was dilated upstream to a 4.5- ⫻ 2.5-cm hypoechogenic mass in the pancreatic head. The main pancreatic duct was dilated to 6 mm in its body and tail portion. No hepatic metastases were apparent. Contrast-enhanced computed tomography (CT) of the abdomen confirmed these findings. When endoscopic retrograde cholangiopancreatography (ERCP) was performed, pancreatogram of the pancreatic duct system demonstrated a clearly annular and nondilated pancreatic duct (Fig. 1). The distal part of the common bile duct was opacified by reflux: its diameter was normal, and a streamlined stenosis of the dorsal pancreatic portion of the common bile duct was noted. The intrahepatic bile ducts were not opacified. Magnetic resonance cholangiopancreatography (MRCP) was performed by using a multislice half-Fourier acquisition singleshot turbo-spin echo (HASTE) technique. Breath-hold, axial, gradient-echo T1-weighted and turbo spin-echo T2-weighted sequences were also performed. MRCP allowed visualization and understanding of all the anomalies observed in the pancreatic anatomy. Magnetic resonance imaging and MRCP provided evidence of a tumor lesion in the pancreatic head and dilatations of the main bile duct, intrahepatic bile ducts, and one pancreatic duct (dorsal duct of a pancreas divisum; Fig. 2). The annular ventral duct enhanced by ERCP, and MRCP showed communication (Fig. 3) with the sub-stenotic main bile duct through the major duodenal

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F. Cholet et al.: Annular pancreas and carcinoma in the dorsal pancreas divisum

Fig. 1. ERCP. Pancreatogram from the major duodenal papilla show an annular pancreatic duct. A Anteroposterior view. B Lateral view.

Fig. 2. MRCP (HASTE; coronal; single shot; effective echo time, 87 ms; acquisition time, 18 s; 6-mm slice thickness) show dilatation of the dorsal pancreatic duct (thin arrow) and the common bile duct (thick arrow).

papilla. An endobiliary prosthesis was placed by using the combined endoscopic-percutaneous transhepatic method, which allowed regression of jaundice. The patient died 3 months later.

Discussion Apart from its exceptional character, this case study is noteworthy because the various pancreatic variants were found as soon as additional examinations were conducted. Indeed,

Fig. 3. MRCP (HASTE; single shot; effective echo time, 87 ms; acquisition time, 18 s; 6-mm slice thickness). Open arrow main bile duct stenosis; small solid arrow communication between the ventral annular pancreatic duct and the common bile duct; large solid arrow proximal part of the dorsal pancreatic duct.

the data from ultrasonography and CT of the abdomen did not completely agree with ERCP findings: the first two techniques showed dilatation of the main bile duct and the main pancreatic duct, whereas ERCP demonstrated a retropancreatic main bile duct of standard diameter and an annular, nondilated pancreatic duct. Therefore, one should emphasize the important contribution of MRCP, which was the only technique to allow understanding of duct abnormal-


ities as a whole. According to the literature, ERCP is the key examination for the diagnosis of AP [4], but this technique has limitations because of anatomic reasons: duodenal stenosis in some cases of complete AP or when the pancreas is drained by one or several ducts directly connected to the second duodenum. Visualization of coexistent PD with ERCP requires catheterization of the minor duodenal papilla. However, in the present case report, catheterization was not possible. Efficacy of contrast enhancement through the minor duodenal papilla falls within 4% to 74% of cases [8]. In conclusion, ERCP is an invasive technique not devoid of morbidity risk [9]. Several recent papers have reported the benefits of MRCP in the diagnosis of AP [10 –13]. MRCP is highly sensitive and better than ERCP for visualizing the pancreatic ducts, especially with the HASTE sequence [14]. However, MRCP using single-shot rapid acquisition with relaxation enhancement may be superior to HASTE for conspicuity of the pancreatic duct [15]. This noninvasive examination allows visualization of not only the pancreatic ducts but also the pancreatic parenchyma around the duodenum, especially if T1-weighted sequences with fat suppression are performed [10, 12, 13]. In other respects, AP can be suspected from an upper gastrointestinal barium series that shows an extrinsic stenosis out-centered from the right side of the second duodenum. The efficacy of endoscopic ultrasonography in AP diagnosis seems clear [16]. This technique assesses whether AP is complete or partial and visualizes signs of early chronic pancreatitis with calcifications: its reported incidence is 14% to 50% of the AP diagnosed in adults [17, 18]. CT of the pancreas may show the pancreatic tissue around the second duodenum [19], but such images are misinterpreted as a thickening of the duodenum. Considering embryonic development, the three buds that will later form the pancreas start developing from the foregut over the fourth week of intrauterine life. The body, tail, and head of the pancreas arise from the dorsal bud. The left ventral bud atrophies quickly, whereas the right one gives rise to the lower part of the pancreas head. The pancreas rotates behind the duodenum and comes to lie under the bud. Usually over the seventh week of embryonic development, the two pancreatic buds fuse together and their respective ducts undergo anastomosis; PD results from a failed fusion. To explain the origin of AP, two opposite theories about embryonic development have been proposed: Lecco [20] assumed that, before rotation, the right ventral bud adheres to the duodenal wall, which is abnormal, and that, over the migration process, it encircles the duodenum with pancreatic tissue. According to Baldwin [21], AP results from failed atrophy of the left ventral bud. However, these theories agree in stating that the ring of tissue from the ventral pancreas around the duodenum causes AP. Lecco’s theory accounts for the permanent annular character of ventral pancreas associating AP with PD. Several pancreatographic classifications have been proposed in the Japanese and Chinese literature: the simplest of these [22] described three different types of AP: in type 1, the fusion of ventral and dorsal ducts

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fails and then results in PD and AP, as in our case report; in type 2, the fusion of the dorsal and ventral pancreas is correct, but the annular duct arises from the main pancreatic duct as a branch; and in type 3, the tail of the annular duct fuses with the dorsal duct to form the main duct. The coexistence of AP with PD is not surprising: the migration of the two buds and the fusion of the respective ducts take place at the same time during embryonic development. To our knowledge, only seven cases have been reported [2, 3, 5, 6]. Assessing the prevalence of associated PD and AP is difficult. A review of 14 cases of AP (including surgery, autopsy, and endoscopy series) estimated a prevalence of 36%. This observation suggests a higher frequency of PD in the presence of AP and thus favors the embryonic theory, which assumes that a failed AP rotation changes the direction of the two pancreatic buds and the fusion of the ventral and dorsal ducts [2]. However, this PD prevalence of 36% with existing AP may be overrated; indeed, the injection of a high-pressure contrast agent by ERCP can show an anatomic connection between the dorsal pancreas and the ventral one without physiologic reality [16]. To our knowledge, this case report is the second about the coexistence of a carcinoma of the dorsal part of a PD with an AP [7]. Although this association is not significant, one should note that cancers in patient with PD have been found in the dorsal pancreas [23, 24]. In addition, this case has shown the utility and diagnostic value of magnetic resonance imaging, including MRCP with HASTE sequence, which is noninvasive and highly sensitive in detecting pancreatic duct variants and parenchymal pancreatic tumors. References 1. Ravitch M, Woods AJ (1950) Annular pancreas. Ann Surg 132: 1116 – 1127 2. Lehman GA, O’Connor KW (1985) Coexistence of annular pancreas and pancreas divisum—ERCP diagnosis. Gastrointest Endosc 31:25–28 3. Perez de Ayala V, Cebria L, Castellanos D, et al. (1991) Association of annular pancreas and pancreas divisum. Endoscopy 31:310 –311 4. Glazer GM, Margulis AR (1979) Annular pancreas: etiology and diagnosis using endoscopic retrograde cholangiopancreatography. Radiology 133:303–306 5. England RE, Newcomer MK, Leung JW, Cotton PB (1995) Case report: annular pancreas divisum—a report of two cases and review of the literature. Br J Radiol 68:324 –328 6. Sevenet F, Vanthournout I, Coche G, Descombes P (1996) Acute pancreatitis disclosing an uncommon form of annular pancreas. Gastroenterol Clin Biol 20:494 – 496 7. Kamisawa T, Tabata I, Isawa T, et al. (1995) Annular pancreas associated with carcinoma in the dorsal part of pancreas divisum. Int J Pancreatol 17:207–211 8. Bernard JP, Sahel J, Giovannini M, Sarles H (1990) Pancreas divisum is a probable cause of acute pancreatitis: a report of 137 cases. Pancreas 5:248 –254 9. Shimizu S, Tada M, Kawai K (1994) Diagnostic ERCP. Endoscopy 26:88 –92 10. Reinhart RD, Brown JJ, Foglia RP, Aliperti G (1994) MR imaging of annular pancreas. Abdom Imaging 19:301–303 11. Lecesne R, Stein L, Reinhold C, Bret PM (1998) MR cholangiopancreatography of annular pancreas. J Comput Assist Tomogr 22:85– 86 12. Chevallier P, Souci J, Buckley MJ, et al. (1999) Annular pancreas: MR imaging including MR cholangiopancreatography (MRCP). Pancreas 18:216 –218 13. Hidaka T, Hirohashi S, Uchida H, et al. (1998) Annular pancreas

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