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Pyelotumour backflow: A manifestation of renal cell carcinoma
Clin. Radiol. (1973) 24, 459-463 PYELOTUMOUR A MANIFESTATION
BACKFLOW:
OF R E N A L C E L L C A R C I N O M A M Y O M. K Y A W
From the Department of Radiology, University of Utah College of Medicine, Salt Lake City, Utah 84112, U.S.A.
The p y e l o g r a p h i c a p p e a r a n c e o f e x t r a v a s a t i o n o f c o n t r a s t m e d i u m f r o m the pelvi-caliceal system into the t u m o u r b e d a n d cavity o f necrotic renal cell c a r c i n o m a s was seen in a r e t r o g r a d e p y e l o g r a m a n d a drip infusion intravenous p y e l o g r a m in two patients. This unique a n d u n c o m m o n l y recognized clinico-radiological p h e n o m e n o n presents clinically as gross h a e m a t u r i a , a n d radiologically as p y e t o t u m o u r backflow. T h e radiological a p p e a r a n c e is characteristic in t h a t i t does n o t resemble a n y o f the w e l l - k n o w n varieties o f the backflow p h e n o m e n o n . I t is considered to b e one o f the r a d i o l o g i c a l manifestations o f renal cell carcinoma, b u t it has been described only superficially in the English literature. R e c o g n i t i o n o f this characteristic radiological feature is i m p o r t a n t because the diagnosis o f renal cell c a r c i n o m a can be m a d e on the p y e l o g r a p h i c a p p e a r a n c e alone, often eliminating the need for further costly a n d t r a u m a t i c diagnostic r a d i o l o g i c a l studies. The radiological features o f the p y e l o t u m o u r backflow as seen in two patients are presented in this report. CLINICAL s y m p t o m s a n d r a d i o l o g i c a l features manifested b y renal cell c a r c i n o m a can be extremely variable a n d deceiving. Clinically a p a t i e n t with renal cell c a r c i n o m a m a y be a s y m p t o m a t i c , or he m a y have s y m p t o m s m i m i c k i n g o t h e r conditions, for instance renal colic. Likewise, roentgenologically the t u m o u r m a y escape notice on the p y e l o g r a m , or its a b n o r m a l features seen on the r o e n t g e n o g r a m m a y simulate o t h e r lesions o f the kidney, for example a benign renal cyst. A m o n g the various manifestations o f renal cell carcinoma, the feature o f p y e l o t u m o u r backflow o r extravasation was seen in two patients. I t occurred during the course o f a s t a n d a r d r e t r o g r a d e p y e l o g r a m in one a n d a high volume drip infusion p y e l o g r a m in the other patient. This unique b u t u n c o m m o n l y recognized clinico-radiological p h e n o m e n o n caused by renal cell c a r c i n o m a presented clinically as gross h a e m a t u r i a a n d radiologically as p y e l o t u m o u r backflow. The p y e l o g r a p h i c features d o n o t resemble any o f the w e l l - k n o w n backflow p h e n o m e n a t h a t have a p p e a r e d in the literature. I n this report, the radiological features o f pyelot u m o u r backflow are p r e s e n t e d as one a d d i t i o n a l manifestation o f renal cell c a r c i n o m a which is believed to be characteristic a n d yet n o t adequately disclosed in the literature. REPORT OF CASES Case 1.--A 50-year-old man developed painless hematuria two days prior to admission. He had a total of five episodes
of gross haematuria during the two days and admitted that he felt weak. There was no previous history of renal disease and his health was otherwise good. Physical examination revealed a palpable mass in file right upper quadrant of the abdomen, which was felt to be separate from the fiver. The rest of the physical findings were normal. Apart from abundant red blood cells in the urine, pertinent laboratory studies were within normal limits. An intravenous pylogram showed a mass in the upper half of the right kidney and the snperior group of calyces appeared compressed (Fig. 1). A retrograde pyelogram demonstrated contrast extravasation from the superior group of calyces into the tumour cavity ("pyelotumour backflow') (Fig. 2). Selective right renal angiogram showed an avascular mass in the upper half of the kidney. There were no tumour vessels. The wall of the mass was thin and smooth but it was not appreciably radiolucent during the nephrographic phase (Fig. 3). The renal vein was visualized and appeared normal. The angiographic impression was that of a benign cyst and an avascular necrotic turnout was thought to be less likely. The patient was operated upon and a right nephrectomy was pcrformed. The pathological diagnosis was necrotic renal cell carcinoma without renal vein involvement. Case 2.--A 57-year-old male was admitted to the hospital with a two week history of inte~Tnittent gross haematuria and right lower quadrant pain. There were no other clinical symptoms and the physical-examination was normal. Urinalysis showed numerous red blood cells; other routine laboratory studies were normal. The clinical impression was that of right ureteral calculus, and an emergency intravenous pyelogram was performed. It was technically unsatisfactory but a mass in the upper pole of right kidney was suspected. A high volume drip infusion intravenous pyelogram was obtained the following day. It confirmed the presence of a mass lesion in the entire upper half of the right kidney (Fig. 4). In addition, contrast extravasation from the pelvicalyceal system into the surrounding tumour was demon-
459
460
CLINICAL RADIOLOGY
FIG. 1 An intravenous pyelogram showing compression of right superior pole calyces by a mass.
strated (Fig. 5, arrow). This extravasation was best appreciated when the films were taken ha the prone position and disappeared in the supine position. Also, irregular nodular indentations were seen in the renal pelvis (Fig. 5) which on pathological examination were shown to be tumour invasion of the renal pelvis. A selective right renal angiogram disclosed turnout vessels which covered nearly 75 ~ of the kidney (Fig. 6). No renal vein was visualized but instead collateral veins were seen, indicating renal vein invasion by carcinoma (Finck and O'Lougblin, 1969). Subsequent inferior venacavogram confirmed the renal vein invasion and occlusion. At operation, an extensive renal tumour was found invading the renal vein and extending approximately two inches into the inferior vena cava. A nephrectomy and wedge resection of inferior vena cava were performed. The pathological diagnosis was renal cell carcinoma with invasion of both the renal pelvis and vein. DISCUSSION
Fro. 2 A retrograde pyelogram of the same patient demonstrating pyelotumour backflow.
E x t r a v a s a t i o n o f c o n t r a s t m e d i u m f r o m the renal p~lvis a n d calyces into v a r i o u s p a r e n c h y m a l spaces a n d a n a t o m i c structures o f the kidney is a wellknown phenomenon. D e p e n d i n g u p o n the a n a t o m i c structure or space that the extravasate leaks into, these p h e n o m e n a , c o m m o n l y k n o w n as ' b a c k f l o w ' o r 'reflux', have been classified as p y e l o - t u b u l a r , pyelo-interstitial, pyelo-sinus, pyelovenous a n d p y e l o - l y m p h a t i c backflow (Olsson, 1948, K o h l e r , 1953). A c c o r d i n g to Olsson they usually are ' r o e n t g e n - d i a g n o s t i c artefacts caused b y the increased pressure in the renal pelvis p r o d u c e d b y the m e t h o d i.e. injection o f c o n t r a s t m e d i u m via a catheter for p y e l o g r a p h y a n d a p p l i c a t i o n o f ureteric c o m p r e s s i o n for u r o g r a p h y (1948)'.
PYELOTUMOUR
BACKFLOW:
A M A N I F E S T A T I O N OF R E N A L C E L L C A R C I N O M A
461
FIG. 3A
FIG. 3B
Fig. 3a--Arterial phase of selective right renal angiogram showing tumour in the superior pole. No tumour vessels seen.
Fig. 3b--Nephrographic phase revealing a large avascular mass in the upper half of the kMney.
Fla. 4 (abo An intravenous pyelogram in supi pole mass #z the ri~ FI6. 5 (rig, A drip infusion intravenous pye revealing pyelotumoi F
462
CLINICAL
RADIOLOGY
pool of contrast agent either infiltrating the tumour substance or outlining the necrotic tumour cavity has a striking radiological appearance. The diagnosis of malignant invasive tumour or necrotic tumour can be established on the basis of pyelographic findings alone. When a patient with renal cell carcinoma experiences gross haematuria, it indicates that an abnormal communication between either a highly invasive vascular tumour or a necrotic tumour and the collecting system has been created. It would therefore, not be unreasonable to assume that such an open channel or pathway might be radiologically demonstrable after injecting contrast medium into the renal pelvis with some pressure. This means that the tumour-created abnormal pathway from the renal pelvis could be demonstrated during a retrograde pyelogram. The nature of the tumour mass or the necrotic cavity partly filled with the extravasated contrast medium may also be visualised. This principle was proven true in the first case where the extravasated contrast medium on a retrograde pyelogram outlined the necrotic tumour cavity (Fig. 2). Similar findings on the retrograde pyelogram were also observed in a recent report by McAanish and Mostafa (1971), in a patient with renal cell carcinoma. Kohler (1953) found one case of pyelotumour backflow among 10 patients with renal cell carcinoma, in his extensive investigation of various backflow phenomena. Olsson (1948) describes pyelotumour backflow that FIG. 6 was seen during excretory urography. Late arterial phase of right selective renal angiogram Theoretically, pyelotumour extravasation may demonstrating tumour vessels and large collateral draining also be demonstrated on the intravenous pyeloveins. gram, provided that there is an adequate amount of contrast medium in the pelvi-calyceal system and effective indirect pressure applied to raise the intraRecently, pyelo-sinus backttow was described in pelvic pressure. This principle was proven true in three patients during a high volume drip infusion the second case where a high volume drip infusion intravenous pyelogram was performed for adequate pyelogram (Hafiz and Rodko, 1970). In addition to these iatrogenic causes, the back- visualisation and distention of the pelvi-calyceal flow phenomenon of patho-physiological sequence structures and when the films were taken in the of events is seen in pyelo-sinus backflow associated prone position (Fig. 5). The prone position not with acute renal colic which is due to the rupture of only permits optimal visualisation of the renal calyceal fornix (Olsson, 1948), and pyelotubular pelvis but also increases the intrapelvic pressure bacldtow in hydronephrosis and pyelonephritis secondary to increased intra-abdominal pressure. (Kohler, 1953). Regardless of the cause, these The effect of compression on the ureters is similar various backflow phenomena do occur in normal to the principle of the abdominal compression band and intact pelvi-calyceal structures secondary to used in routine intravenous pyelography. If these tumour invasion (Kohler, 1953; McAanish and various backflow phenomena may occur during retrograde pyelography in the normal and intact Mostafa, 1971; Olsson, 1948). The pyelographic appearance of such extra- pelvi-calyceal system, then it is not surprising to see vasated contrast medium into the tumour itself such extravasation from a partially or completely does not have the features of normally identifiable destroyed renal pelvis and calyces due to direct anatomic spaces. This nondescript and undefined invasion by the tumour.
PYELOTUMOUR BACKFLOW: A MANIFESTATION OF RENAL CELL CARCINOMA A l t h o u g h u n i n t e n t i o n a l a n d unforseeable in the two patients presented, there is a theoretical risk o f spreading the t u m o u r cells into the blood stream t h r o u g h the process o f extravasation d u r i n g a retrograde or i n t r a v e n o u s pyelogram with a b d o m i n a l compression. However, such a n a s s u m p t i o n is based o n more or less u n f o u n d e d evidence a n d the added practical risk due to such diagnostic procedures is p r o b a b l y negligible. V o n Schreeb a n d his associates (1967) f o u n d that the risk of spreading t u m o u r cells from diagnostic renal punctures is negligible. Furthermore, percutaneous p u n c t u r e of renal cysts is considered safe a n d is being performed regularly at m a n y institutions for the diagnosis a n d detection of m a l i g n a n c y in renal cysts. W h e n a poorly outlined space occupying lesion is seen d u r i n g i n t r a v e n o u s pyelography, extravasated contrast agent into the t u m o u r mass should b e searched for. It m a y require re-injection o f c o n t r a s t m e d i u m , b u t it m a y prove worthwhile a n d valuable i n f o r m a t i o n might be o b t a i n e d at a m i n i m a l cost a n d inconvenience to the patient. I f p y e l o t u m o u r backflow i s d e m o n s t r a t e d in a n
463
i n t r a v e n o u s pyelogram, further diagnostic investigation m a y n o t be necessary, except for the determination of the extent of t u m o u r .
REFERENCES FINCK, E. J. & O'LOUGHLIN,B. J. (1969). Collateral Vein Sign: Angiographic Demonstration of Renal Vein Invasion by Renal Ceil Carcinoma. Radiology, 92, 1256-1261. FORD, W. H. & PALUmNSKAS,A. G. (1967). Renal Extravasation During Excretory Urography Using Abdominal Compression. Journal o f Urology, 97, 983-986. HAFIZ, A. & RODKO, E. A. (1970). Extravasation of Contrast Material During Excretory Pyelography. Journal Canadian Association of Radiology, 21, 46-52. KOHLER, R. (1953). Investigations of Backflow in Retrograde Pyelography. Roentgenologieal and Clinical Study. Acta Radiologica (Supp.), 99. MeAANISrI,L. N. & MOSTAFA,H. M. (1971). Pyelocancerous Backflow. A Diagnostic Radiological Sign for Renal Cell Carcinoma. Journal of Urology, 105, 491. OLSSON, O. (1948). Studies on Backflow in Excretory Urography. Acta Radiologica (Suppl.), 70. VON SCHREEB,T., ARNER, O., SKOVSTED,G., W[CKSTAD,N. (1967). Renal Adenocarcinoma. Is there a risk of spreading tumour cells in diagnostic puncture? Scandinavian Journal of Urology & Nephrology, 1, 270-276.
BOOK REVIEW Ultrasonics in Clinical Diagnosis. Edited by P. N. T. WELLS.
Published by Churchill Livingstones. Price £3.00. In his preface, the editor notes that this book is particularly suitable for candidates for higher examinations in radiology and radiography. It brings together a description of the physical principles involved, the various clinical applications and an assessment of the safety of ultrasound techniques. In doing so it remedies the absence of an up-todate review of the field of diagnostic ultrasound. The first section, written by Professor Wells, deals in some depth with the physical principles of ultrasound and the ways in which various diagnostic systems are constructed. Some of the physical explanations may appear a little daunting to the clinician, but this section is well written and illustrated and provides a necessary basis for the understanding of the clinical applications. The clinical techniques are covered by a number of distinguished authors. Dr. White's account of ultrasonic investigations of the brain rightly points to the difficulties that can arise from unskilled use of A scope techniques. He may however create too much of a mystique about the process, as conventional scanning can be carried out competently by a trained technician, provided
there is close clinical liaison and follow up. His approach to the automated mid-line techniques is more optimistic and he obviously feels that this may enable mid-line scanning to be more widely and usefully employed. Professor Donald has produced a clear and a comprehensive report on the use of sonar in obstetrics and gynaecology, a few more details as to technique would be of great help. Dr Ross's contribution on ultrasonic investigation of the heart provides an excellent description of technique, followed by an explanation of results and possible artefacts. In a field of rapid expansion, it is inevitable that a book such as this cannot be entirely up-to-date. The section on the urinary tract does not do full justice to the scope of ultrasound investigation in this field. Tbere is, for example, no mention of prostate scanning. This book is highly suitable as an introduction to the field of diagnostic ultrasound in general, the illustrations are in general adequate and there are excellent references to those who wish to explore the various clinical applications in greater depth. R. K. LFvIcK
BACKFLOW:
OF R E N A L C E L L C A R C I N O M A M Y O M. K Y A W
From the Department of Radiology, University of Utah College of Medicine, Salt Lake City, Utah 84112, U.S.A.
The p y e l o g r a p h i c a p p e a r a n c e o f e x t r a v a s a t i o n o f c o n t r a s t m e d i u m f r o m the pelvi-caliceal system into the t u m o u r b e d a n d cavity o f necrotic renal cell c a r c i n o m a s was seen in a r e t r o g r a d e p y e l o g r a m a n d a drip infusion intravenous p y e l o g r a m in two patients. This unique a n d u n c o m m o n l y recognized clinico-radiological p h e n o m e n o n presents clinically as gross h a e m a t u r i a , a n d radiologically as p y e t o t u m o u r backflow. T h e radiological a p p e a r a n c e is characteristic in t h a t i t does n o t resemble a n y o f the w e l l - k n o w n varieties o f the backflow p h e n o m e n o n . I t is considered to b e one o f the r a d i o l o g i c a l manifestations o f renal cell carcinoma, b u t it has been described only superficially in the English literature. R e c o g n i t i o n o f this characteristic radiological feature is i m p o r t a n t because the diagnosis o f renal cell c a r c i n o m a can be m a d e on the p y e l o g r a p h i c a p p e a r a n c e alone, often eliminating the need for further costly a n d t r a u m a t i c diagnostic r a d i o l o g i c a l studies. The radiological features o f the p y e l o t u m o u r backflow as seen in two patients are presented in this report. CLINICAL s y m p t o m s a n d r a d i o l o g i c a l features manifested b y renal cell c a r c i n o m a can be extremely variable a n d deceiving. Clinically a p a t i e n t with renal cell c a r c i n o m a m a y be a s y m p t o m a t i c , or he m a y have s y m p t o m s m i m i c k i n g o t h e r conditions, for instance renal colic. Likewise, roentgenologically the t u m o u r m a y escape notice on the p y e l o g r a m , or its a b n o r m a l features seen on the r o e n t g e n o g r a m m a y simulate o t h e r lesions o f the kidney, for example a benign renal cyst. A m o n g the various manifestations o f renal cell carcinoma, the feature o f p y e l o t u m o u r backflow o r extravasation was seen in two patients. I t occurred during the course o f a s t a n d a r d r e t r o g r a d e p y e l o g r a m in one a n d a high volume drip infusion p y e l o g r a m in the other patient. This unique b u t u n c o m m o n l y recognized clinico-radiological p h e n o m e n o n caused by renal cell c a r c i n o m a presented clinically as gross h a e m a t u r i a a n d radiologically as p y e l o t u m o u r backflow. The p y e l o g r a p h i c features d o n o t resemble any o f the w e l l - k n o w n backflow p h e n o m e n a t h a t have a p p e a r e d in the literature. I n this report, the radiological features o f pyelot u m o u r backflow are p r e s e n t e d as one a d d i t i o n a l manifestation o f renal cell c a r c i n o m a which is believed to be characteristic a n d yet n o t adequately disclosed in the literature. REPORT OF CASES Case 1.--A 50-year-old man developed painless hematuria two days prior to admission. He had a total of five episodes
of gross haematuria during the two days and admitted that he felt weak. There was no previous history of renal disease and his health was otherwise good. Physical examination revealed a palpable mass in file right upper quadrant of the abdomen, which was felt to be separate from the fiver. The rest of the physical findings were normal. Apart from abundant red blood cells in the urine, pertinent laboratory studies were within normal limits. An intravenous pylogram showed a mass in the upper half of the right kidney and the snperior group of calyces appeared compressed (Fig. 1). A retrograde pyelogram demonstrated contrast extravasation from the superior group of calyces into the tumour cavity ("pyelotumour backflow') (Fig. 2). Selective right renal angiogram showed an avascular mass in the upper half of the kidney. There were no tumour vessels. The wall of the mass was thin and smooth but it was not appreciably radiolucent during the nephrographic phase (Fig. 3). The renal vein was visualized and appeared normal. The angiographic impression was that of a benign cyst and an avascular necrotic turnout was thought to be less likely. The patient was operated upon and a right nephrectomy was pcrformed. The pathological diagnosis was necrotic renal cell carcinoma without renal vein involvement. Case 2.--A 57-year-old male was admitted to the hospital with a two week history of inte~Tnittent gross haematuria and right lower quadrant pain. There were no other clinical symptoms and the physical-examination was normal. Urinalysis showed numerous red blood cells; other routine laboratory studies were normal. The clinical impression was that of right ureteral calculus, and an emergency intravenous pyelogram was performed. It was technically unsatisfactory but a mass in the upper pole of right kidney was suspected. A high volume drip infusion intravenous pyelogram was obtained the following day. It confirmed the presence of a mass lesion in the entire upper half of the right kidney (Fig. 4). In addition, contrast extravasation from the pelvicalyceal system into the surrounding tumour was demon-
459
460
CLINICAL RADIOLOGY
FIG. 1 An intravenous pyelogram showing compression of right superior pole calyces by a mass.
strated (Fig. 5, arrow). This extravasation was best appreciated when the films were taken ha the prone position and disappeared in the supine position. Also, irregular nodular indentations were seen in the renal pelvis (Fig. 5) which on pathological examination were shown to be tumour invasion of the renal pelvis. A selective right renal angiogram disclosed turnout vessels which covered nearly 75 ~ of the kidney (Fig. 6). No renal vein was visualized but instead collateral veins were seen, indicating renal vein invasion by carcinoma (Finck and O'Lougblin, 1969). Subsequent inferior venacavogram confirmed the renal vein invasion and occlusion. At operation, an extensive renal tumour was found invading the renal vein and extending approximately two inches into the inferior vena cava. A nephrectomy and wedge resection of inferior vena cava were performed. The pathological diagnosis was renal cell carcinoma with invasion of both the renal pelvis and vein. DISCUSSION
Fro. 2 A retrograde pyelogram of the same patient demonstrating pyelotumour backflow.
E x t r a v a s a t i o n o f c o n t r a s t m e d i u m f r o m the renal p~lvis a n d calyces into v a r i o u s p a r e n c h y m a l spaces a n d a n a t o m i c structures o f the kidney is a wellknown phenomenon. D e p e n d i n g u p o n the a n a t o m i c structure or space that the extravasate leaks into, these p h e n o m e n a , c o m m o n l y k n o w n as ' b a c k f l o w ' o r 'reflux', have been classified as p y e l o - t u b u l a r , pyelo-interstitial, pyelo-sinus, pyelovenous a n d p y e l o - l y m p h a t i c backflow (Olsson, 1948, K o h l e r , 1953). A c c o r d i n g to Olsson they usually are ' r o e n t g e n - d i a g n o s t i c artefacts caused b y the increased pressure in the renal pelvis p r o d u c e d b y the m e t h o d i.e. injection o f c o n t r a s t m e d i u m via a catheter for p y e l o g r a p h y a n d a p p l i c a t i o n o f ureteric c o m p r e s s i o n for u r o g r a p h y (1948)'.
PYELOTUMOUR
BACKFLOW:
A M A N I F E S T A T I O N OF R E N A L C E L L C A R C I N O M A
461
FIG. 3A
FIG. 3B
Fig. 3a--Arterial phase of selective right renal angiogram showing tumour in the superior pole. No tumour vessels seen.
Fig. 3b--Nephrographic phase revealing a large avascular mass in the upper half of the kMney.
Fla. 4 (abo An intravenous pyelogram in supi pole mass #z the ri~ FI6. 5 (rig, A drip infusion intravenous pye revealing pyelotumoi F
462
CLINICAL
RADIOLOGY
pool of contrast agent either infiltrating the tumour substance or outlining the necrotic tumour cavity has a striking radiological appearance. The diagnosis of malignant invasive tumour or necrotic tumour can be established on the basis of pyelographic findings alone. When a patient with renal cell carcinoma experiences gross haematuria, it indicates that an abnormal communication between either a highly invasive vascular tumour or a necrotic tumour and the collecting system has been created. It would therefore, not be unreasonable to assume that such an open channel or pathway might be radiologically demonstrable after injecting contrast medium into the renal pelvis with some pressure. This means that the tumour-created abnormal pathway from the renal pelvis could be demonstrated during a retrograde pyelogram. The nature of the tumour mass or the necrotic cavity partly filled with the extravasated contrast medium may also be visualised. This principle was proven true in the first case where the extravasated contrast medium on a retrograde pyelogram outlined the necrotic tumour cavity (Fig. 2). Similar findings on the retrograde pyelogram were also observed in a recent report by McAanish and Mostafa (1971), in a patient with renal cell carcinoma. Kohler (1953) found one case of pyelotumour backflow among 10 patients with renal cell carcinoma, in his extensive investigation of various backflow phenomena. Olsson (1948) describes pyelotumour backflow that FIG. 6 was seen during excretory urography. Late arterial phase of right selective renal angiogram Theoretically, pyelotumour extravasation may demonstrating tumour vessels and large collateral draining also be demonstrated on the intravenous pyeloveins. gram, provided that there is an adequate amount of contrast medium in the pelvi-calyceal system and effective indirect pressure applied to raise the intraRecently, pyelo-sinus backttow was described in pelvic pressure. This principle was proven true in three patients during a high volume drip infusion the second case where a high volume drip infusion intravenous pyelogram was performed for adequate pyelogram (Hafiz and Rodko, 1970). In addition to these iatrogenic causes, the back- visualisation and distention of the pelvi-calyceal flow phenomenon of patho-physiological sequence structures and when the films were taken in the of events is seen in pyelo-sinus backflow associated prone position (Fig. 5). The prone position not with acute renal colic which is due to the rupture of only permits optimal visualisation of the renal calyceal fornix (Olsson, 1948), and pyelotubular pelvis but also increases the intrapelvic pressure bacldtow in hydronephrosis and pyelonephritis secondary to increased intra-abdominal pressure. (Kohler, 1953). Regardless of the cause, these The effect of compression on the ureters is similar various backflow phenomena do occur in normal to the principle of the abdominal compression band and intact pelvi-calyceal structures secondary to used in routine intravenous pyelography. If these tumour invasion (Kohler, 1953; McAanish and various backflow phenomena may occur during retrograde pyelography in the normal and intact Mostafa, 1971; Olsson, 1948). The pyelographic appearance of such extra- pelvi-calyceal system, then it is not surprising to see vasated contrast medium into the tumour itself such extravasation from a partially or completely does not have the features of normally identifiable destroyed renal pelvis and calyces due to direct anatomic spaces. This nondescript and undefined invasion by the tumour.
PYELOTUMOUR BACKFLOW: A MANIFESTATION OF RENAL CELL CARCINOMA A l t h o u g h u n i n t e n t i o n a l a n d unforseeable in the two patients presented, there is a theoretical risk o f spreading the t u m o u r cells into the blood stream t h r o u g h the process o f extravasation d u r i n g a retrograde or i n t r a v e n o u s pyelogram with a b d o m i n a l compression. However, such a n a s s u m p t i o n is based o n more or less u n f o u n d e d evidence a n d the added practical risk due to such diagnostic procedures is p r o b a b l y negligible. V o n Schreeb a n d his associates (1967) f o u n d that the risk of spreading t u m o u r cells from diagnostic renal punctures is negligible. Furthermore, percutaneous p u n c t u r e of renal cysts is considered safe a n d is being performed regularly at m a n y institutions for the diagnosis a n d detection of m a l i g n a n c y in renal cysts. W h e n a poorly outlined space occupying lesion is seen d u r i n g i n t r a v e n o u s pyelography, extravasated contrast agent into the t u m o u r mass should b e searched for. It m a y require re-injection o f c o n t r a s t m e d i u m , b u t it m a y prove worthwhile a n d valuable i n f o r m a t i o n might be o b t a i n e d at a m i n i m a l cost a n d inconvenience to the patient. I f p y e l o t u m o u r backflow i s d e m o n s t r a t e d in a n
463
i n t r a v e n o u s pyelogram, further diagnostic investigation m a y n o t be necessary, except for the determination of the extent of t u m o u r .
REFERENCES FINCK, E. J. & O'LOUGHLIN,B. J. (1969). Collateral Vein Sign: Angiographic Demonstration of Renal Vein Invasion by Renal Ceil Carcinoma. Radiology, 92, 1256-1261. FORD, W. H. & PALUmNSKAS,A. G. (1967). Renal Extravasation During Excretory Urography Using Abdominal Compression. Journal o f Urology, 97, 983-986. HAFIZ, A. & RODKO, E. A. (1970). Extravasation of Contrast Material During Excretory Pyelography. Journal Canadian Association of Radiology, 21, 46-52. KOHLER, R. (1953). Investigations of Backflow in Retrograde Pyelography. Roentgenologieal and Clinical Study. Acta Radiologica (Supp.), 99. MeAANISrI,L. N. & MOSTAFA,H. M. (1971). Pyelocancerous Backflow. A Diagnostic Radiological Sign for Renal Cell Carcinoma. Journal of Urology, 105, 491. OLSSON, O. (1948). Studies on Backflow in Excretory Urography. Acta Radiologica (Suppl.), 70. VON SCHREEB,T., ARNER, O., SKOVSTED,G., W[CKSTAD,N. (1967). Renal Adenocarcinoma. Is there a risk of spreading tumour cells in diagnostic puncture? Scandinavian Journal of Urology & Nephrology, 1, 270-276.
BOOK REVIEW Ultrasonics in Clinical Diagnosis. Edited by P. N. T. WELLS.
Published by Churchill Livingstones. Price £3.00. In his preface, the editor notes that this book is particularly suitable for candidates for higher examinations in radiology and radiography. It brings together a description of the physical principles involved, the various clinical applications and an assessment of the safety of ultrasound techniques. In doing so it remedies the absence of an up-todate review of the field of diagnostic ultrasound. The first section, written by Professor Wells, deals in some depth with the physical principles of ultrasound and the ways in which various diagnostic systems are constructed. Some of the physical explanations may appear a little daunting to the clinician, but this section is well written and illustrated and provides a necessary basis for the understanding of the clinical applications. The clinical techniques are covered by a number of distinguished authors. Dr. White's account of ultrasonic investigations of the brain rightly points to the difficulties that can arise from unskilled use of A scope techniques. He may however create too much of a mystique about the process, as conventional scanning can be carried out competently by a trained technician, provided
there is close clinical liaison and follow up. His approach to the automated mid-line techniques is more optimistic and he obviously feels that this may enable mid-line scanning to be more widely and usefully employed. Professor Donald has produced a clear and a comprehensive report on the use of sonar in obstetrics and gynaecology, a few more details as to technique would be of great help. Dr Ross's contribution on ultrasonic investigation of the heart provides an excellent description of technique, followed by an explanation of results and possible artefacts. In a field of rapid expansion, it is inevitable that a book such as this cannot be entirely up-to-date. The section on the urinary tract does not do full justice to the scope of ultrasound investigation in this field. Tbere is, for example, no mention of prostate scanning. This book is highly suitable as an introduction to the field of diagnostic ultrasound in general, the illustrations are in general adequate and there are excellent references to those who wish to explore the various clinical applications in greater depth. R. K. LFvIcK