Medial Indentation of the Duodenal Sweep by Common Bile Duct Dilatation

Transcription

1 233 Medial Indentation of the Duodenal Sweep by Common Bile Duct Dilatation Richard Palmer Gold1 The dilated common bile duct has long been recognized as a cause for a smooth, tubular impression across the duodenal bulb or immediate postbulbar duodenum. Only scattered references suggest that a smooth indentation on the medial aspect of the descending duodenum might also be due to an enlarged, tortuous common duct. Three cases of this condition are reported. The dilated common duct impression can mimic a pancreatic mass. While computed tomography, ultrasonography, or transhepatic cholangiography readily suggest the true diagnosis, potential pitfalls in patient management are possible when the first radiographic procedure is an upper gastrointestinal series. Received August 17, 1978; accepted after revision April 11, Department of Radiology, Columbia University, College of Physicians and Surgeons, and Columbia-Presbyterian Medical Center, 622 W. 168th St., New York, NY AJR 133: , August o3x/79/ $00.00 American Roentgen Ray Society Compression of the duodenal sweep by choledochal cysts has been described [1, 2], as has the tubular impression across the duodenal bulb and immediate postbulbar duodenum by a dilated common bile duct. [3, 4] Not so well documented is the compression of the medial aspect of the second duodenum by a common bile duct that is dilated and often tortuous due to a distal obstruction. Case Case 1 Reports A 73-year-old jaundiced man complained of pruritus and epigastric pain. After similar complaints 3#{189} years before, he was found to have cholecystolithiasis and choledocholithiasis, and had a cholecystectomy and common bile duct exploration. Evaluation during the present admission showed a marked impression on the medial portion of the second duodenum (fig. 1 A), and diagnosis of pancreatic mass was entertamed. A skinny needle transhepatic cholangiogram (fig. 1 B) showed a massively dilated intra- and extrahepatic biliary tree with obstruction of the very distal common bile duct. Although barium was not given orally during transhepatic cholangiography, superimposing the two studies (fig. 1 C) revealed that most of the impression on the duodenum was due to the dilated common bile duct. A persistent defect in the duodenum at the site of ductal insertion (fig. 1 C) raised the possibility of a small mass, and a 2 cm ampullary carcinoma was discovered at surgery. Case 2 A 74-year-old woman had abdominal pain, nausea and vomiting, jaundice, and a kg weight loss over 2 months. Laboratory examination disclosed a total serum bilirubin of 20 mg/i 00 ml and an alkaline phosphatase of 975 IU. Upper gastrointestinal series (fig. 2A) demonstrated a 4 cm smooth impression on the medial aspect of the second duodenum,

2 234 GOLD AJR:133, August 1979 A Fig. 1.-Case 1. Smooth mass impression along medial aspect of duodenal sweep (arrows). B, Transhepatic cholangiography. Common bile duct hugely dilated and slightly tortuous. c, Indentation on second part of duodenum. Tracing of common duct superimposed on barium-filled duodenum. Separate small mass (arrows) was 2 cm ampullary carcinoma. and subsequent transhepatic cholangiography (fig. 2B) showed a dilated intra- and extrahepatic biliary tree, stones in the gallbladder, and a slightly irregular contour to the distal common bile duct as it entered the region of the ampulla. Surgery and pathology revealed cholelithiasis and a 7 mm x 1 cm well differentiated biliary carcinoma growing circumferentially around the very distal common bile duct. B Case 3 A 38-year-old white woman with cutaneous neurofibromatosis suffered from intermittent pruritus and jaundice for 3 years. Total serum bilirubin was 7.8 mg/100 ml and upper gastrointestinal series demonstrated a smooth, 5 cm impression on the medial aspect of the descending duodenum and a second smaller mass in

3 AJR:133, August 1979 DUODENUM COMPRESSED BY DILATED COMMON DUCT 235 A Fig. 2.-Case 2. A, Smooth, double impression (arrows) on descending duodenum. B, Transhepatic cholangiography. Tortuous, dilated common duct impressing medial duodenum. Slight contour irregularity of distal duct caused by cholangiocarcinoma. the third portion of the duodenum (fig. 3A). Duodenoscopy showed a submucosal mass in the third portion at the location of a low papilla of Vater, making retrograde cannulation impossible. Transhepatic cholangiography (fig. 3B) revealed a markedly dilated intraand extrahepatic biliary tree with the common bile duct measuring almost 3.5 cm and tapering to enter the duodenum via a very low lying ampulla. Although the submucosal mass was not readily appreciated on the barium studies, the endoscopic preoperative impression was a strategically placed neurofibroma. However, surgery and pathology disclosed that the 2 cm mass distorting the ampulla was a nonfunctioning, ectopic, islet cell adenoma. Discussion The close proximity of the common bile duct, gallbladder, duodenal bulb, and descending duodenum serves to explain how enlargement of the extrahepatic biliary tree will compress parts of the barium filled duodenum. This phenomenon has been noted for some time. In 1 946, Brown and Harper [5] first suggested that the dilated ducts exert pressure upon the duodenum, often resulting in dilatation of the duodenum bulb and at times causing partial obstruction. They suggested that the right lateral decubitus position would show this pressure defect on the superior flexure of the duodenum. In 1 954, Hodes et al. [4] noted that the [common bile duct] defect, as a rule lies in the immediate post-bulbar region, behind which most common ducts lie. Subsequent authors have continued to refer to the bulb being deformed from a dilated common bile duct [5-7], as a post-bulbar impression caused by a widened common bile duct [3], impression on the proximal duodenum B [8], the dilated common duct deforming the duodenum at high noon [9], and impression on the duodenum where the dilated bile duct passes behind it, usually at the junction of the first and second parts [1 0]. While discussing the radiology of jaundice in their monograph, Eaton and Ferrucci [1 1 ] mentioned that the typical finding [of a dilated common bile duct] is an extrinsic indentation defect on the apical portion of the duodenal bulb. The defect is rather sharply defined and fairly tubular in appearance [1 1 ]. In a more recent monograph, Berk [1 2] again reiterates this relationship by commenting that the distended duct produces a tubular impression on the duodenum, usually in the post-bulbar segment. It has periodically been hinted that the dilated bile duct may also compress portions of the second duodenumspecifically, the medial aspect of the duodenal sweep. Hodes et al. [4] discussing the radiology of pancreatic carcinoma, speculated that sometimes the medial aspect of the duodenal loop assumes a double contour or profile. Whether this is due to invasion plus pressure by tumor or some other cause, the medial border of the loop seems reduplicated. Seven years later, Salik [3] stated that the widened common bile duct may produce a flattening of the inner part of the duodenum. He produced a small line drawing illustrating the postbulbar impression of the enlarged common duct, but whether his double contour on the descending duodenum was due to the common bile duct or an associated pancreatic carcinoma was not clear. In 1 976, Whalen [8] mentioned that dilatation of the common bile duct... indents the duodenal bulb, or occasionally, the

4 236 GOLD AJR:133, August 1979 A Fig. 3.-Case 3. A, Frame from 35 mm upper gastrointestinal examination. Smooth mass impression on medial duodenum (straight arrows). Second impression in third part of duodenum (curved arrows) at site of low ampulla and islet cell adenoma. B, Transhepatic cholangiography. Enormous common bile duct markedly convex toward descending duodenum. proximal descending duodenum, but only Jacques and Bream [1 3] have produced an example of this duodenal mass effect from a dilated common duct. While the anatomic relation of the dilated common bile duct to the descending duodenum has been alluded to by others, our three cases reemphasize a specific point. Although compression with narrowing of the second part of the duodenal loop is highly suggestive of a carcinoma of the head of the pancreas... and usually only when growths are too large to offer much hope of successful surgical resection [10], this same compression can be due to an enlarged common bile duct with the underlying pathology being a benign as well as a malignant lesion. As might be expected the impressions are extremely smooth with no evidence of duodenal wall rigidity, mucosal ulceration, encasement of the sweep, reverse 3 signs of Frostberg, or angulation, tethering, or fixation of the duodenal mucosa. Intraluminal masses may be present around the ampulla, particularly in those cases with papillary edema due to an impacted stone or pancreatitis [1 4, 1 5], a small ampullary or pancreatic carcinoma, or a benign tumor of the ampullary region. Differential diagnosis for postbulbar and bulbar impressions of the common duct includes duodenal peristalsis, the cystogastrocolic ligament, angulation of a normal duodenum, a dilated portal vein or hepatic artery, quadrate lobe of the liver, and a mass in the porta hepatis [1 1 ]. With a second finding of a double density in the duodenal sweep, the chances of a pancreatic or peripancreatic mass are B high. However, either or both impressions can be due to a large, tortuous common bile duct. With the advent of skinny needle transhepatic cholangiography, computed tomography of the abdomen, and ultrasonography, it is doubtful that either of these mass impressions on the duodenum in a jaundiced patient would be misdiagnosed for long. In fact, in our own prospective series of jaundiced patients, routine upper gastrointestinal series in those with no evidence of liver metastases was not helpful. Nevertheless, for those patients who do come for barium studies first, for either poorly defined symptoms or for a workup of jaundice, the smooth medial indentation on the duodenal sweep should be evaluated cautiously and should at least suggest the diagnosis of a dilated common bile duct. REFERENCES 1. Han SY, Collins LC, Wright RM: Choledochal cyst: report of five cases. Clin Radio! 20 : , Liebner EJ: Roentgen study of congenital choledochal cystspre and post op analysis of five cases. AJR 80: , Salik JO: Pancreatic cancer and its early roentgenologic recognition. AJR 86:1-28, Hodes PJ, Pendergrass EP, Winston NJ: Pancreatic, ductal and vaterian neoplasms: their roentgen manifestations. Radiology 62 : 1-1 5, Brown 5, Harper FG: A new roentgen sign in extrahepatic biliary disease. Radiology 47 : , McGlone FB, Robertson DS, Grogan JM: The roentgenologic

5 AJR:133, August 1979 DUODENUM COMPRESSED BY DILATED COMMON DUCT 237 manifestations of pancreatic tumors. Gastroenterology 31: , Eyler WA, Clark MD, Rian AL: An evaluation of roentgen signs of pancreatic enlargement. JAMA 1 81 : , Whalen JP: Masses in the right upper quandrant, in Radiology of the Abdomen: Anatomic Basis, Philadelphia, Lea & Febiger, 1976, pp Bilbao MK, Rosch J, Frische LH, Potter CT: Hypotonic duodenography in the diagnosis of pancreatic disease. Semin Roentgenol 3: , Young WB: Obstructive jaundice, the radiologist, the surgeon and the patient. AJR 119:4-39, Eaton SB, Ferrucci JT: The radiology of jaundice, in Radiology ofthe Pancreas andduodenum, Philadelphia, Saunders, 1973, pp Berk AN: Barium studies of the gastrointestinal tract, in Radiology of the Gallbladder and Bile Ducts, Philadelphia, Saunders, 1 977, pp Jacques PF, Bream CA: Barium duodenography as an adjunct to percutaneous trans-hepatic cholangiography. AJR 130: , Bree AL, Flynn RE: Hypotonic duodenography in obstructive jaundice. AJR 116: , Eaton SB, Ferrucci JT, Benedict KT, Margulis AF: Diagnosis of choledocholithiasis by barium duodenal examination. Radiology 102: , 1972

6 This article has been cited by: 1. P. J. Finch, J. Haddock, A. Grundy Duodenal pseudotumour: a silent impacted common bile duct calculus. Postgraduate Medical Journal 65:768, [Crossref]