Gastrointestinal
Radiology
Gastrointest Radiol 4, 343-347 (1979)
Mediastinal Pancreatic Pseudocyst A l b e r t W e i n f e l d a n d J a c k O. K a p l a n Department of Radiology (R~130), University of Miami School of Medicine, Miami, Florida, USA
Abstract. T h e e x t e n s i o n o f a p a n c r e a t i c p s e u d o c y s t i n t o t h e m e d i a s t i n u m is a d i f f i c u l t c l i n i c a l a n d rad i o g r a p h i c d i a g n o s i s . T h e c h e s t r o e n t g e n o g r a m reveals a r e t r o c a r d i a c m a s s in a p a t i e n t w i t h n o n s p e c i f i c upper abdominal and chest complaints. Usually there is a p r e c e d i n g h i s t o r y o f a l c o h o l i s m o r p a n c r e a t i t i s . T h e u p p e r g a s t r o i n t e s t i n a l series o f t e n d e m o n s t r a t e s t y p i c a l d i s p l a c e m e n t o f the d i s t a l e s o p h a g u s a n t e r i o r l y a n d to t h e left. T h e v a l u e o f c o m p u t e d t o m o g r a p h y is i l l u s t r a t e d . C o r r e c t p r e o p e r a t i v e d i a g n o s i s is i m p o r t a n t f o r p r o p e r s u r g i c a l t r e a t m e n t , since a m e d i a s t i n a l p s e u d o c y s t is b e s t m a n a g e d w i t h o u t t h o r a c o t o m y .
Key words: M e d i a s t i n a l m a s s - P a n c r e a s - P s e u d o cyst.
P a n c r e a t i c p s e u d o c y s t is c a u s e d b y a u t o d i g e s t i o n o f the p a n c r e a s a n d is u s u a l l y s e c o n d a r y to i n f l a m m a tion, trauma, or pancreatic duct obstruction. A pseud o c y s t is a c o l l e c t i o n o f p a n c r e a t i c s e c r e t i o n s , b l o o d , a n d c e l l u l a r debris, w h i c h o f t e n b r e a k s t h r o u g h t h e pancreatic capsule. The collection becomes encysted d u e to the l o c a l i n f l a m m a t o r y r e s p o n s e . T h e cyst w a l l contains proliferating fibroblasts but no epithelium. O c c a s i o n a l l y , the s e r o s a o f a n a d j a c e n t v i s c u s m a y f o r m p a r t o f t h e cyst wall. T h e u s u a l l o c a t i o n is w i t h i n the lesser s a c ; h o w e v e r , as the p s e u d o c y s t e n l a r g e s , it dissects a l o n g tissue p l a n e s o f least r e s i s t a n c e a n d m a y p r e s e n t as a m a s s in o t h e r l o c a t i o n s . T h r e e cases o f m e d i a s t i n a l e x t e n s i o n o f p a n c r e a t i c p s e u d o c y s t are p r e s e n t e d , a n d t h e 20 cases p r e v i o u s l y r e p o r t e d in t h e E n g l i s h l i t e r a t u r e are r e v i e w e d [1-17]. Address reprint requests to: Albert Weinfeld, M.D., Department of
Radiology, University of Miami School of Medicine, P.O. Box 016960, Miami, FLA 33101, USA
Case Reports Case 1
A 47-year-old white housewife was admitted with a 2-week history of left upper quadrant pain, occasional nausea and vomiting. She had been previously hospitalized for a similar episode with a presumptive diagnosis of peptic ulcer disease. Past medical history was unremarkable except for consumption of one pint of alcohol per day for more than 15 years. Admission chest X-ray (Fig. 1) revealed a mediastinai mass which had not been present 7 months earlier. Frontal tomograms demonstrated the mass to be thoracoabdominal in position (Fig. 2). On physical examination the liver was enlarged. The liver scan confirmed this and showed changes of diffuse hepatocellular disease. All laboratory studies including liver enzymes and serum amylase were normal. An upper gastrointestinal series revealed anterior and lateral displacement of the distal esophagus (Fig. 3). The stomach appeared normal. Arteriography, performed to rule out aortic aneurysm, demonstrated an avascular mass posterior to the left lobe of the liver. There was displacement of the inferior vena cava to the right. Abdominal exploration revealed a thick-walled pseudocyst originating in the head of the pancreas with extension into the mediastinum. Internal drainage via a Roux-en-Y cystojejunostomy was performed.
Case 2
A 52-year-old black male was admitted with a 6-month history of intermittent right upper quadrant pain and emesis. The patient was a known chronic alcoholic with multiple previous admissions for pancreatitis. Physical examination revealed epigastric and right upper quadrant tenderness without a palpable mass. Admission laboratory tests revealed elevated liver enzymes and elevated serum and urinary amylase. The chest films (Fig. 4) showed a left retrocardiac mass, and abdominal films showed lateral displacement of the air bubble in the gastric fundus. An upper gastrointestinal examination demonstrated a retrogastric mass with irregularity of the posterior wall of the stomach. There was extrinsic pressure on the distal esophagus (Fig. 5). Abdominal exploration revealed an immature pancreatic pseudocyst posterior to the stomach with dissection into the mediastinum. External drainage to the skin was performed.
9
0 3 6 4 - 2 3 5 6 / 7 9 / 0 0 0 4 ~ ) 3 4 3 $01.00 1979 S p r i n g e r - V e r l a g N e w Y o r k Inc.
344
A. Weinfeld and J.O. Kaplan: Mediastinal Pancreatic Pseudocyst
Fig. 1. Case 1. A Frontal chest X-ray reveals a right mediastinal mass at the level of T11-T12 (arrows). B Lateral chest X-ray reveals the mass to be retrocardiac in location (arrows)
Fig.2. Case 1. Frontal t o m o g r a m demonstrates that the mediastinal mass extends below the diaphragm (arrows)
Fig. 3. Case 1. Frontal esophagram demonstrates lateral displacement of the distal esophagus (arrow). Anterior displacement was shown on other views
A. Weinfeld and J.O. Kaplan: Mediastinal Pancreatic Pseudocyst
345
Fig. 4. Case 2. Frontal (A) and lateral (B) roentgenograms of the chest reveal a left retrocardiac mass (arrows)
Fig. 5. Case 2. Frontal esophagram demonstrates lateral displacement of the distal esophagus and proximal stomach (arrow) as well as irregularity of the medial aspect of the gastric fundus
Fig. 6. Case 3. Frontal view from upper gastrointestinal series reveals lateral displacement of the distal esophagus and body of the stomach (arrows)
Case 3
Physical examination revealed a 6 cm epigastric mass which was tender to palpation. All laboratory tests were normal except for elevation of the serum urinary amylase. Chest and abdominal films revealed a retrocardiac mass and lateral displacement of the stomach. Upper gastrointestinal examination showed anterior and left lateral displacement of the esophagus and confirmed an extrinsic mass effect on the stomach
A 37-year-old white male chronic alcoholic was admitted with 1 week of severe upper abdominal pain associated with nausea and vomiting. Intermittent episodes of pain had occurred for the past 6 m o n t h s . One year prior to admission, he had external drainage of a pancreatic pseudocyst,
346
A. Weinfeld and J.O. Kaplan : Mediastinal Pancreatic Pseudocyst
Fig. 7. Computed tomographic section of another patient with a pancreatic pseudocyst. This scan is through the upper abdomen and lower thorax and reveals a pseudocyst in the left upper quadrant (large arrow) with extension through the aortic hiatus in the retrocrural space (small arrow). No retrocardiac mass was present in the chest roentgenograms of this patient. (Courtesy of Dr. L. Caplan, Baptist Hospital, Miami, Florida)
(Fig. 6). An ultrasound study revealed a 6-cm pancreatic pseudocyst arising from the body and tail of the pancreas. The retrocardiac mass could not be visualized by ultrasound. After initial medical therapy for pancreatitis, abdominal exploration revealed a mature retrogastric pancreatic pseudocyst which extended into the mediastinum. Internal drainage via a Roux-en-Y cystojejunostomy was performed.
Discussion
Pancreatic pseudocyst is rarely considered in the differential diagnosis of a mediastinal mass. However, the presence of a retrocardiac mass, causing displacement of the distal esophagus, in a patient with a prior history of alcoholism or pancreatitis should suggest this diagnosis. Our three patients were chronic alcoholics, and all had typical displacement of the lower esophagus anteriorly and to the left [1]. Most pancreatic mediastinal pseudocysts are located inferiorly in the posterior mediastinum, and lie immediately retrocardiac. This position is explained by the route of spread of the pseudocyst into the mediastinum, which is almost always through the esophageal or aortic hiatus. There is only a single case report of mediastinal extension as a result of diaphragmatic erosion [12]. Chest X-rays in our patients showed a mediastinal mass, but none of the X-rays showed a pleural effusion. The presence or absence of a pleural effusion is not helpful in the diagnosis of mediastinal pancreatic pseudocyst, especially since pleural effusion is not uncommon in patients with uncomplicated ab-
dominal pancreatic pseudocyst [18, 19]. All of our patients denied chest symptoms. Many of the previously reported patients with mediastinal pseudocyst had chest pain or dyspnea. These symptoms may have been caused by the frequently accompanying pleural effusions. Abdominal pain, in association with nausea and vomiting, was present in our three patients, and was readily explained by pancreatic inflammation or by the abdominal portion of the pancreatic pseudocyst. Only one of our three patients had a palpable abdominal mass. Of the 20 previously reported cases, only three patients had a palpable abdominal mass. A possible explanation is decompression of the pseudocyst into the mediastinum [12]. Ultrasound and computed tomography are the best available means for assessing pancreatic disease [20, 21]. These radiologic methods can usually characterize pancreatic pseudocysts and delineate their extent. Because of the difficulty of scanning under the sternum, as seen in our case 3, ultrasound may not be able to demonstrate the superior spread of pseudocyst into the mediastinum. Computed tomography can be used as an alternative in this situation since it can easily demonstrate the retrocrural anatomy and the mediastinum (Fig. 7). A correct preoperative diagnosis of the mediastinal extension of a pancreatic pseudocyst is essential since thoracotomy is useless. Ideal management is abdominal exploration with internal drainage via a cystoenteric anastomosis. After adequate internal drainage, the mediastinal component of the pseudo-
A. Weinfeld and J.O. Kaplan: Mediastinal Pancreatic Pseudocyst cyst rapidly disappears without any treatment specifically d i r e c t e d t o w a r d t h e t h o r a x [12]. Acknowledgment. Gratitude is expressed to Mrs. Dorene A. Ferris for her secretarial assistance. This project is supported in part by BSR Grant H-8413R.
References 1. Kirchner SG, Heller RM, Smith CW: Pancreatic pseudocyst of the mediastinum. Radiology 123: 37-42, 1977 2. Anderson W J, Skinner DB, Zuidema GD, Cameron JL : Chronic pancreatic pleural effusions. Surg Gynecol Obstet 137."827 830, 1973 3. Edlin P: Mediastinal pseudocyst of the pancreas. Case report and discussion. Gastroenterology 17.'96 102, 1951 4. McClintock JT, McFee JL, Quimby RL : Pancreatic pseudocyst presenting as a mediastinal tumor. JAMA 192.573 574, 1965 5. Laird CA, Clagett OT: Mediastinal pseudocyst of the pancreas in a child: report of a case. Surgery 60.'465 469, 1966 6. Galligan JJ, Williams HJ : Pancreatic pseudocysts in childhood. Unusual case with mediastinal extension. Am J Dis Child 112.479-482, 1966 7. Sybers HD, Shelp WD, Morrissey JF : Pseudocysts of the pancreas with fistulous extension into the neck. N Engl J Med 278:1058-1059, 1968 8. Clauss RH, Wilson DW : Pancreatic pseudocyst of the mediastinum. J Thorac Surg 35:795 801, 1958 9. Gee W, Foster ED, Doohen D J: Mediastinal pancreatic pseudocyst. Ann Surg 169:420 424, 1969
347 10. Weidmann P, Rutishauser W, Siegenthaler W, Senning A: Mediastinal pseudocyst of the pancreas. Am J Med 46: 454-459, 1969 11. Reynes CJ, Love L: Mediastinal pseudocyst. Radiology 92:115-116, 1969 12. Jaffe BM, Ferguson TB, Holtz S, Shields JB: Mediastinal pancreatic pseudocysts. Am J Surg 124:600-606, 1972 13. Christensen NM, Demling R, Mathewson C Jr : Unusual manifestations of pancreatic pseudocysts and their surgical management. Am J Surg 130:199-204, 1975 14. Asokan S, Alagratnam D, Eftaha M, Radhakrishan J, Lira LT, Teresi M: Ultrasonography of a mediastinal pseudocyst. Am J Roentgenol 129:923 924, 1977 15. Dewey GC, Clark RE: Middle mediastinal and retrogastric mass. Chest 69:97-98, 1976 16. Morton JR, Newell AA: Mediastinal pseudocyst. J Maine Med Assoc 65:246-248, 1974 17. Gooding GA: Pseudocyst of the pancreas with mediastinal extension: an ultrasonographic demonstration. J Clin Ultrasound 5(2) : 121-123, 1977 18. Caravati CM, Ashworth JS, Frederick P: Pancreatic pseudocysts. JAMA 197:572 576, 1966 19. Thomford NR, Jesseph JE: Pseudocyst of the pancreas. Am J Surg 188:86 94, 1969 20. Levitt RG, Geisse GG, Sagel SS, Stanley RJ, Evens RG, Koehler RE, Jost RG: Complementary use of ultrasound and computed tomography in studies of the pancreas and kidney. Radiology 126:149-i52, 1978 2I. Husband JE, Meire HB, Kreel L: Comparison of ultrasound and computer-assisted tomography in pancreatic diagnosis. Br J Radiol 50.855-862, 1977 Received: March 16, 1979; accepted: April 13, 1979
Radiology
Gastrointest Radiol 4, 343-347 (1979)
Mediastinal Pancreatic Pseudocyst A l b e r t W e i n f e l d a n d J a c k O. K a p l a n Department of Radiology (R~130), University of Miami School of Medicine, Miami, Florida, USA
Abstract. T h e e x t e n s i o n o f a p a n c r e a t i c p s e u d o c y s t i n t o t h e m e d i a s t i n u m is a d i f f i c u l t c l i n i c a l a n d rad i o g r a p h i c d i a g n o s i s . T h e c h e s t r o e n t g e n o g r a m reveals a r e t r o c a r d i a c m a s s in a p a t i e n t w i t h n o n s p e c i f i c upper abdominal and chest complaints. Usually there is a p r e c e d i n g h i s t o r y o f a l c o h o l i s m o r p a n c r e a t i t i s . T h e u p p e r g a s t r o i n t e s t i n a l series o f t e n d e m o n s t r a t e s t y p i c a l d i s p l a c e m e n t o f the d i s t a l e s o p h a g u s a n t e r i o r l y a n d to t h e left. T h e v a l u e o f c o m p u t e d t o m o g r a p h y is i l l u s t r a t e d . C o r r e c t p r e o p e r a t i v e d i a g n o s i s is i m p o r t a n t f o r p r o p e r s u r g i c a l t r e a t m e n t , since a m e d i a s t i n a l p s e u d o c y s t is b e s t m a n a g e d w i t h o u t t h o r a c o t o m y .
Key words: M e d i a s t i n a l m a s s - P a n c r e a s - P s e u d o cyst.
P a n c r e a t i c p s e u d o c y s t is c a u s e d b y a u t o d i g e s t i o n o f the p a n c r e a s a n d is u s u a l l y s e c o n d a r y to i n f l a m m a tion, trauma, or pancreatic duct obstruction. A pseud o c y s t is a c o l l e c t i o n o f p a n c r e a t i c s e c r e t i o n s , b l o o d , a n d c e l l u l a r debris, w h i c h o f t e n b r e a k s t h r o u g h t h e pancreatic capsule. The collection becomes encysted d u e to the l o c a l i n f l a m m a t o r y r e s p o n s e . T h e cyst w a l l contains proliferating fibroblasts but no epithelium. O c c a s i o n a l l y , the s e r o s a o f a n a d j a c e n t v i s c u s m a y f o r m p a r t o f t h e cyst wall. T h e u s u a l l o c a t i o n is w i t h i n the lesser s a c ; h o w e v e r , as the p s e u d o c y s t e n l a r g e s , it dissects a l o n g tissue p l a n e s o f least r e s i s t a n c e a n d m a y p r e s e n t as a m a s s in o t h e r l o c a t i o n s . T h r e e cases o f m e d i a s t i n a l e x t e n s i o n o f p a n c r e a t i c p s e u d o c y s t are p r e s e n t e d , a n d t h e 20 cases p r e v i o u s l y r e p o r t e d in t h e E n g l i s h l i t e r a t u r e are r e v i e w e d [1-17]. Address reprint requests to: Albert Weinfeld, M.D., Department of
Radiology, University of Miami School of Medicine, P.O. Box 016960, Miami, FLA 33101, USA
Case Reports Case 1
A 47-year-old white housewife was admitted with a 2-week history of left upper quadrant pain, occasional nausea and vomiting. She had been previously hospitalized for a similar episode with a presumptive diagnosis of peptic ulcer disease. Past medical history was unremarkable except for consumption of one pint of alcohol per day for more than 15 years. Admission chest X-ray (Fig. 1) revealed a mediastinai mass which had not been present 7 months earlier. Frontal tomograms demonstrated the mass to be thoracoabdominal in position (Fig. 2). On physical examination the liver was enlarged. The liver scan confirmed this and showed changes of diffuse hepatocellular disease. All laboratory studies including liver enzymes and serum amylase were normal. An upper gastrointestinal series revealed anterior and lateral displacement of the distal esophagus (Fig. 3). The stomach appeared normal. Arteriography, performed to rule out aortic aneurysm, demonstrated an avascular mass posterior to the left lobe of the liver. There was displacement of the inferior vena cava to the right. Abdominal exploration revealed a thick-walled pseudocyst originating in the head of the pancreas with extension into the mediastinum. Internal drainage via a Roux-en-Y cystojejunostomy was performed.
Case 2
A 52-year-old black male was admitted with a 6-month history of intermittent right upper quadrant pain and emesis. The patient was a known chronic alcoholic with multiple previous admissions for pancreatitis. Physical examination revealed epigastric and right upper quadrant tenderness without a palpable mass. Admission laboratory tests revealed elevated liver enzymes and elevated serum and urinary amylase. The chest films (Fig. 4) showed a left retrocardiac mass, and abdominal films showed lateral displacement of the air bubble in the gastric fundus. An upper gastrointestinal examination demonstrated a retrogastric mass with irregularity of the posterior wall of the stomach. There was extrinsic pressure on the distal esophagus (Fig. 5). Abdominal exploration revealed an immature pancreatic pseudocyst posterior to the stomach with dissection into the mediastinum. External drainage to the skin was performed.
9
0 3 6 4 - 2 3 5 6 / 7 9 / 0 0 0 4 ~ ) 3 4 3 $01.00 1979 S p r i n g e r - V e r l a g N e w Y o r k Inc.
344
A. Weinfeld and J.O. Kaplan: Mediastinal Pancreatic Pseudocyst
Fig. 1. Case 1. A Frontal chest X-ray reveals a right mediastinal mass at the level of T11-T12 (arrows). B Lateral chest X-ray reveals the mass to be retrocardiac in location (arrows)
Fig.2. Case 1. Frontal t o m o g r a m demonstrates that the mediastinal mass extends below the diaphragm (arrows)
Fig. 3. Case 1. Frontal esophagram demonstrates lateral displacement of the distal esophagus (arrow). Anterior displacement was shown on other views
A. Weinfeld and J.O. Kaplan: Mediastinal Pancreatic Pseudocyst
345
Fig. 4. Case 2. Frontal (A) and lateral (B) roentgenograms of the chest reveal a left retrocardiac mass (arrows)
Fig. 5. Case 2. Frontal esophagram demonstrates lateral displacement of the distal esophagus and proximal stomach (arrow) as well as irregularity of the medial aspect of the gastric fundus
Fig. 6. Case 3. Frontal view from upper gastrointestinal series reveals lateral displacement of the distal esophagus and body of the stomach (arrows)
Case 3
Physical examination revealed a 6 cm epigastric mass which was tender to palpation. All laboratory tests were normal except for elevation of the serum urinary amylase. Chest and abdominal films revealed a retrocardiac mass and lateral displacement of the stomach. Upper gastrointestinal examination showed anterior and left lateral displacement of the esophagus and confirmed an extrinsic mass effect on the stomach
A 37-year-old white male chronic alcoholic was admitted with 1 week of severe upper abdominal pain associated with nausea and vomiting. Intermittent episodes of pain had occurred for the past 6 m o n t h s . One year prior to admission, he had external drainage of a pancreatic pseudocyst,
346
A. Weinfeld and J.O. Kaplan : Mediastinal Pancreatic Pseudocyst
Fig. 7. Computed tomographic section of another patient with a pancreatic pseudocyst. This scan is through the upper abdomen and lower thorax and reveals a pseudocyst in the left upper quadrant (large arrow) with extension through the aortic hiatus in the retrocrural space (small arrow). No retrocardiac mass was present in the chest roentgenograms of this patient. (Courtesy of Dr. L. Caplan, Baptist Hospital, Miami, Florida)
(Fig. 6). An ultrasound study revealed a 6-cm pancreatic pseudocyst arising from the body and tail of the pancreas. The retrocardiac mass could not be visualized by ultrasound. After initial medical therapy for pancreatitis, abdominal exploration revealed a mature retrogastric pancreatic pseudocyst which extended into the mediastinum. Internal drainage via a Roux-en-Y cystojejunostomy was performed.
Discussion
Pancreatic pseudocyst is rarely considered in the differential diagnosis of a mediastinal mass. However, the presence of a retrocardiac mass, causing displacement of the distal esophagus, in a patient with a prior history of alcoholism or pancreatitis should suggest this diagnosis. Our three patients were chronic alcoholics, and all had typical displacement of the lower esophagus anteriorly and to the left [1]. Most pancreatic mediastinal pseudocysts are located inferiorly in the posterior mediastinum, and lie immediately retrocardiac. This position is explained by the route of spread of the pseudocyst into the mediastinum, which is almost always through the esophageal or aortic hiatus. There is only a single case report of mediastinal extension as a result of diaphragmatic erosion [12]. Chest X-rays in our patients showed a mediastinal mass, but none of the X-rays showed a pleural effusion. The presence or absence of a pleural effusion is not helpful in the diagnosis of mediastinal pancreatic pseudocyst, especially since pleural effusion is not uncommon in patients with uncomplicated ab-
dominal pancreatic pseudocyst [18, 19]. All of our patients denied chest symptoms. Many of the previously reported patients with mediastinal pseudocyst had chest pain or dyspnea. These symptoms may have been caused by the frequently accompanying pleural effusions. Abdominal pain, in association with nausea and vomiting, was present in our three patients, and was readily explained by pancreatic inflammation or by the abdominal portion of the pancreatic pseudocyst. Only one of our three patients had a palpable abdominal mass. Of the 20 previously reported cases, only three patients had a palpable abdominal mass. A possible explanation is decompression of the pseudocyst into the mediastinum [12]. Ultrasound and computed tomography are the best available means for assessing pancreatic disease [20, 21]. These radiologic methods can usually characterize pancreatic pseudocysts and delineate their extent. Because of the difficulty of scanning under the sternum, as seen in our case 3, ultrasound may not be able to demonstrate the superior spread of pseudocyst into the mediastinum. Computed tomography can be used as an alternative in this situation since it can easily demonstrate the retrocrural anatomy and the mediastinum (Fig. 7). A correct preoperative diagnosis of the mediastinal extension of a pancreatic pseudocyst is essential since thoracotomy is useless. Ideal management is abdominal exploration with internal drainage via a cystoenteric anastomosis. After adequate internal drainage, the mediastinal component of the pseudo-
A. Weinfeld and J.O. Kaplan: Mediastinal Pancreatic Pseudocyst cyst rapidly disappears without any treatment specifically d i r e c t e d t o w a r d t h e t h o r a x [12]. Acknowledgment. Gratitude is expressed to Mrs. Dorene A. Ferris for her secretarial assistance. This project is supported in part by BSR Grant H-8413R.
References 1. Kirchner SG, Heller RM, Smith CW: Pancreatic pseudocyst of the mediastinum. Radiology 123: 37-42, 1977 2. Anderson W J, Skinner DB, Zuidema GD, Cameron JL : Chronic pancreatic pleural effusions. Surg Gynecol Obstet 137."827 830, 1973 3. Edlin P: Mediastinal pseudocyst of the pancreas. Case report and discussion. Gastroenterology 17.'96 102, 1951 4. McClintock JT, McFee JL, Quimby RL : Pancreatic pseudocyst presenting as a mediastinal tumor. JAMA 192.573 574, 1965 5. Laird CA, Clagett OT: Mediastinal pseudocyst of the pancreas in a child: report of a case. Surgery 60.'465 469, 1966 6. Galligan JJ, Williams HJ : Pancreatic pseudocysts in childhood. Unusual case with mediastinal extension. Am J Dis Child 112.479-482, 1966 7. Sybers HD, Shelp WD, Morrissey JF : Pseudocysts of the pancreas with fistulous extension into the neck. N Engl J Med 278:1058-1059, 1968 8. Clauss RH, Wilson DW : Pancreatic pseudocyst of the mediastinum. J Thorac Surg 35:795 801, 1958 9. Gee W, Foster ED, Doohen D J: Mediastinal pancreatic pseudocyst. Ann Surg 169:420 424, 1969
347 10. Weidmann P, Rutishauser W, Siegenthaler W, Senning A: Mediastinal pseudocyst of the pancreas. Am J Med 46: 454-459, 1969 11. Reynes CJ, Love L: Mediastinal pseudocyst. Radiology 92:115-116, 1969 12. Jaffe BM, Ferguson TB, Holtz S, Shields JB: Mediastinal pancreatic pseudocysts. Am J Surg 124:600-606, 1972 13. Christensen NM, Demling R, Mathewson C Jr : Unusual manifestations of pancreatic pseudocysts and their surgical management. Am J Surg 130:199-204, 1975 14. Asokan S, Alagratnam D, Eftaha M, Radhakrishan J, Lira LT, Teresi M: Ultrasonography of a mediastinal pseudocyst. Am J Roentgenol 129:923 924, 1977 15. Dewey GC, Clark RE: Middle mediastinal and retrogastric mass. Chest 69:97-98, 1976 16. Morton JR, Newell AA: Mediastinal pseudocyst. J Maine Med Assoc 65:246-248, 1974 17. Gooding GA: Pseudocyst of the pancreas with mediastinal extension: an ultrasonographic demonstration. J Clin Ultrasound 5(2) : 121-123, 1977 18. Caravati CM, Ashworth JS, Frederick P: Pancreatic pseudocysts. JAMA 197:572 576, 1966 19. Thomford NR, Jesseph JE: Pseudocyst of the pancreas. Am J Surg 188:86 94, 1969 20. Levitt RG, Geisse GG, Sagel SS, Stanley RJ, Evens RG, Koehler RE, Jost RG: Complementary use of ultrasound and computed tomography in studies of the pancreas and kidney. Radiology 126:149-i52, 1978 2I. Husband JE, Meire HB, Kreel L: Comparison of ultrasound and computer-assisted tomography in pancreatic diagnosis. Br J Radiol 50.855-862, 1977 Received: March 16, 1979; accepted: April 13, 1979
