Surg Radiol Anat DOI 10.1007/s00276-014-1349-8
ANATOMIC VARIATIONS
Extrarenal calyces: a rare renal congenital anomaly Tulika Gupta • Suresh K. Goyal • Anjali Aggarwal Daisy Sahni • A. K. Mandal
•
Received: 21 April 2014 / Accepted: 10 July 2014 Ó Springer-Verlag France 2014
Keywords Congenital anomalies Urogenital anomalies Extrarenal calyces Renal collecting system
this anomaly, major calyces (sometimes minor calyces) and renal pelvis lie outside the renal parenchyma. Extrarenal calyces may be associated with other anomalous conditions and diseases. Extrarenal calyces have been detected incidentally [6] (during routine cadaveric dissection, autopsy or surgical exploration) or diagnosed, when investigated for its complications such as stasis, calculi and infection [7]. Case reports describing extrarenal calyces are sparse in the literature. Recently, owing to increased awareness and recognition of this entity, more cases have been reported. The rarity of this anomaly makes its preoperative diagnosis difficult and lack of its knowledge may lead to inadvertent injury to pelvicalyceal system during surgery. We are presenting two cases of extrarenal calyces that we came across during routine cadaveric dissection.
Introduction
Case report
The congenital anomalies of urogenital system are not uncommon. Approximately 30 % of the children born with congenital anomalies tend to have urogenital anomalies [10]. Among these, anomalies of renal collecting system are relatively rare and complex. These anomalies can range from agenesis of the collecting system to duplication of the collecting system. Extrarenal calyces are one of the infrequently found anomalies of the renal collecting system. In
Case 1
Abstract The congenital anomalies of urogenital system are not uncommon. The anomalies of renal collecting system form a complex subset of urogenital anomalies. Among these, extrarenal calyces are one of the infrequently found anomalies of the renal collecting system. Extrarenal calyces may be detected incidentally or when thoroughly investigated for its associated complications. We report two cases of extrarenal calyces characterized by the presence of major calyces and renal pelvis outside the renal parenchyma. The awareness of this anomaly can help in making the definitive preoperative diagnosis and prevent injury to pelvicalyceal system during surgery.
T. Gupta (&) S. K. Goyal A. Aggarwal D. Sahni Department of Anatomy, Postgraduate Institute of Medical Education and Research, Sector, 12, Chandigarh 160012, India e-mail: [email protected]; [email protected] A. K. Mandal Department of Urology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
A 17-year male died of head injury. There was no previous history of renal disease. During routine cadaveric dissection, left kidney was normal in position and size, while right kidney was seen lying in lower lumbar region and measured 9 9 5 9 3.5 cm. Its hilum was facing anteriorly and situated at the level of bifurcation of aorta. Its anterior surface was lobulated in appearance with five visible lobes. The renal pelvis and four major calyces were lying outside the renal parenchyma (Fig. 1). The extrarenal length of four calyces was 4, 2, 2 and 1 respectively. These calyces, before exiting the hilum, were seen running on anterior surface of kidney creating well-defined indentations on its surface. All calyces, just before entering the kidney, were slightly dilated giving club-shaped appearance. At hilum,
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Surg Radiol Anat Fig. 1 a Anterior aspect of the right kidney. b Posterior aspect of right kidney. MC1, MC2, MC3 and MC4 extrarenal major calyces, RP renal pelvis, U ureter, AO aorta, SRA, MRA and IRA superior, middle and inferior renal arteries respectively, RCIA right common iliac artery, LCIA left common iliac artery, arrow indicates superior renal artery entering posterior surface of kidney
Fig. 2 a Posterior aspect of the right kidney. b Posterior aspect of the right kidney after reflection of the pelvicalyceal system. c Anterior flat aspect of right kidney. d Partial frontal section of kidney to illustrate the anatomy of the renal papillae. Zoomed view of the same is shown below. MC1, MC2, MC3 and MC4 extrarenal major calyces, RV renal vein, RA renal artery, RP renal pelvis, U ureter, hollow arrow marks extrarenal branching of the renal artery into segmental arteries, bold arrow shows formation of the renal vein from segmental veins
the structures lying from lateral to medial side were inferior renal artery, renal pelvis and superior and middle renal arteries. The posterior surface of this kidney was flat with deep groove on lateral border. In this case, kidney was supplied by three renal arteries. Superior renal artery originated from lateral aspect of aorta 2.5 cm above bifurcation of aorta. Near the medial border
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of the kidney, superior renal artery divided into two branches: one entering the anterior and other posterior surface of kidney near upper pole. The middle renal artery was largest among three and it originated from the ventral aspect of aorta 1.5 cm above bifurcation of aorta. It entered the kidney approximately in the middle of hilum. The inferior renal artery, longest in course, took origin from
Surg Radiol Anat
right common iliac artery 1 cm below aortic bifurcation. It curved around lower most calyx before entering the kidney near lateral border. Renal veins accompanied renal arteries. Case 2 A 50-year male died of hypovolemic shock following road traffic accident. He had no previous history of renal disease. On routine cadaveric dissection, both right and left kidney were normally placed. Right kidney measured 10.5 9 5.5 9 3 cm. The hilum was elliptical and elongated; and it was on posteromedial aspect of the kidney. The renal pelvis and four major calyces were lying outside the renal parenchyma. The extrarenal lengths of four calyces were 3, 1, 1 and 0.5, respectively (Fig. 2). At hilum, the structures lying from anterior to posterior were renal artery, renal vein and renal pelvis. There was no gross evidence of hydronephrosis. There was single renal artery originating from aorta, which divided into four segmental arteries at the hilum. The segmental veins accompanied segmental arteries which formed single renal vein draining into IVC. The anterior surface of the kidney was flat. The left kidney was normal in shape and position.
Discussion Extrarenal calyces are among the rarest anomalies of the renal collecting system. This anomaly was first described in 1925 by Eisendrath [3] and reported sporadically by few authors [2, 9]. This entity was again described and reviewed by Malament [4]. There are only 20 cases reported so far [8]. Extrarenal calyces are reported more commonly on left side than on right side. The left side was involved twice as frequently as the right [2]. In our series, both cases of extrarenal calyces were of right-sided kidney. Kidney with extrarenal calyces is usually associated with other anomalies such as bifid ureter, renal ectopia, horseshoe kidney and renal dysgenesis, etc [4, 5]. Out of all the cases reported so far, majority had associated ectopic kidney [1, 7]. In case 1, extrarenal calyces were associated with ectopic kidney and showed features of non-rotation (as hilum was facing anteriorly). During fetal development, as the kidney ascents, it is accompanied by rotation. Therefore, unaccented kidney (ectopic kidney) is usually associated with varied degrees of non-rotation. Ectopic kidneys with associated variations in vascular supply are not common. During fetal life, as kidneys ascent from pelvis to posterior abdominal wall, they are supplied by segmental mesonephric arteries at different levels. In ectopia, unaccented kidney retains the vascular pattern corresponding to the developmental stage at which their ascent is arrested. In case 1 of extrarenal calyces with renal
ectopia, there were three renal arteries. The superior and middle renal arteries took origin from aorta at a level lower than normal origin and inferior renal artery originated from common iliac artery. Some significant differences are apparent in these two cases of extrarenal calyces: case 1 = ectopic kidney, multiple arteries, deep renal grooves, very long calyces (twice longer than in case 2) and narrow renal pelvis. Case 2 = orthotopic kidney, normal vascularisation, no external grooves, normal calyceal length, normal wideness of the renal pelvis. These differences might indicate different mechanism at play in each of these two cases. The exact cause of extrarenal calyces is not clear. It has been hypothesized that this anomaly could be due to a disparity resulting from slow development of metanephric tissue and to a relatively rapid development of ureteric bud. The slow development of metanephric tissue could delay its attachment to the collecting system, leading to development of first- and second-order collecting system outside the renal parenchyma. Conversely, with the rapid development of ureteric bud, calyceal system could well develop prior to its coalescence with the nephrogenic mass [1, 4]. This might be the possible mechanism for mal development in the case 2. It is also hypothesized that failure of ureteric bud to indent the nephrogenic mass fails to provide stimulus for rotation and ascent, accounting for the association of extrarenal calyces with renal ectopia and non-rotation [1]. This pathogenesis might have led to the renal development in the case 1. The diagnosis of this congenital anomaly is usually made when clinical symptoms warrant detailed investigations or incidentally when explored for associated disease. The preoperative diagnosis of this anomaly is usually difficult. Plain radiography and ultrasonography are not of much significance. Excretory urography provides good anatomic information about the collecting system. Diagnosis may be made when renal pelvis appears to be situated outside the renal shadow and calyces extend to kidney with incurvation resembling the ‘‘prongs of a small hand garden rake’’ [4]. The extrarenal calyces being unsupported are easily distended on retrograde pyelography, thus may create a false impression of hydronephrosis. It may be concluded that knowledge of this anomaly can help the radiologists in making a preoperative diagnosis of this entity and can prevent wrong diagnosis of hydronephrosis on retrograde pyelography. The awareness of this entity among surgeons can prevent inadvertent injury to extrarenal collecting system during surgery. Conflict of interest of interest.
The authors declare that they have no conflict
Ethical standards The experiments comply with the current laws of the country in which they were performed.
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Surg Radiol Anat
References 1. Dretler SP, Pfister R, Hendren WH (1970) Extrarenal calyces in the ectopic kidney. J Urol 103(4):406 2. Dunn GP, Gibson TE (1951) Extrarenal calyces. Urol Cutan Rev 55:259–260 3. Eisendrath DN (1925) Report of a case of hydronephrosis in kidney with extrarenal calyces. J Urol 13:51–53 4. Malament M, Schwartz B, Nagamatsu GR (1961) Extrarenal calyces: their relationship to renal disease. Am J Roentgenol Radium Ther Nucl Med 86:823–824 5. Mohanty C, Ray B, Samaratunga U et al (2002) Horseshoe kidney with extrarenal calyces: a case report. J Anat Soc India 51:57–59
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6. Nataraju G, Nandeesh BN, Gayathri MN (2009) Extrarenal calyces: a rare anomaly of the renal collecting system. Indian J Pathol Microbiol 52(3):368–369 7. Rao DV, Sharma SK, Rao MS et al (1972) Extrarenal calyces with complications: a case report. Aust N Z J Surg 42(2):178–179 8. Taha SA, Hashish MH, Eldarawany HM, Barakat AE, Al-Zahrani AA (2006) Renal dysplasia with extrarenal calyces. Saudi Med J 27(3):392–394 9. Vessen LL (1933) Extrarenal calyces. J Urol 30:487–488 10. Zivkovic D, Varga J, Grebeldinger S, Borisev V (2005) Ureteral triplication: a case report. Med Preg 58:592–595
ANATOMIC VARIATIONS
Extrarenal calyces: a rare renal congenital anomaly Tulika Gupta • Suresh K. Goyal • Anjali Aggarwal Daisy Sahni • A. K. Mandal
•
Received: 21 April 2014 / Accepted: 10 July 2014 Ó Springer-Verlag France 2014
Keywords Congenital anomalies Urogenital anomalies Extrarenal calyces Renal collecting system
this anomaly, major calyces (sometimes minor calyces) and renal pelvis lie outside the renal parenchyma. Extrarenal calyces may be associated with other anomalous conditions and diseases. Extrarenal calyces have been detected incidentally [6] (during routine cadaveric dissection, autopsy or surgical exploration) or diagnosed, when investigated for its complications such as stasis, calculi and infection [7]. Case reports describing extrarenal calyces are sparse in the literature. Recently, owing to increased awareness and recognition of this entity, more cases have been reported. The rarity of this anomaly makes its preoperative diagnosis difficult and lack of its knowledge may lead to inadvertent injury to pelvicalyceal system during surgery. We are presenting two cases of extrarenal calyces that we came across during routine cadaveric dissection.
Introduction
Case report
The congenital anomalies of urogenital system are not uncommon. Approximately 30 % of the children born with congenital anomalies tend to have urogenital anomalies [10]. Among these, anomalies of renal collecting system are relatively rare and complex. These anomalies can range from agenesis of the collecting system to duplication of the collecting system. Extrarenal calyces are one of the infrequently found anomalies of the renal collecting system. In
Case 1
Abstract The congenital anomalies of urogenital system are not uncommon. The anomalies of renal collecting system form a complex subset of urogenital anomalies. Among these, extrarenal calyces are one of the infrequently found anomalies of the renal collecting system. Extrarenal calyces may be detected incidentally or when thoroughly investigated for its associated complications. We report two cases of extrarenal calyces characterized by the presence of major calyces and renal pelvis outside the renal parenchyma. The awareness of this anomaly can help in making the definitive preoperative diagnosis and prevent injury to pelvicalyceal system during surgery.
T. Gupta (&) S. K. Goyal A. Aggarwal D. Sahni Department of Anatomy, Postgraduate Institute of Medical Education and Research, Sector, 12, Chandigarh 160012, India e-mail: [email protected]; [email protected] A. K. Mandal Department of Urology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
A 17-year male died of head injury. There was no previous history of renal disease. During routine cadaveric dissection, left kidney was normal in position and size, while right kidney was seen lying in lower lumbar region and measured 9 9 5 9 3.5 cm. Its hilum was facing anteriorly and situated at the level of bifurcation of aorta. Its anterior surface was lobulated in appearance with five visible lobes. The renal pelvis and four major calyces were lying outside the renal parenchyma (Fig. 1). The extrarenal length of four calyces was 4, 2, 2 and 1 respectively. These calyces, before exiting the hilum, were seen running on anterior surface of kidney creating well-defined indentations on its surface. All calyces, just before entering the kidney, were slightly dilated giving club-shaped appearance. At hilum,
123
Surg Radiol Anat Fig. 1 a Anterior aspect of the right kidney. b Posterior aspect of right kidney. MC1, MC2, MC3 and MC4 extrarenal major calyces, RP renal pelvis, U ureter, AO aorta, SRA, MRA and IRA superior, middle and inferior renal arteries respectively, RCIA right common iliac artery, LCIA left common iliac artery, arrow indicates superior renal artery entering posterior surface of kidney
Fig. 2 a Posterior aspect of the right kidney. b Posterior aspect of the right kidney after reflection of the pelvicalyceal system. c Anterior flat aspect of right kidney. d Partial frontal section of kidney to illustrate the anatomy of the renal papillae. Zoomed view of the same is shown below. MC1, MC2, MC3 and MC4 extrarenal major calyces, RV renal vein, RA renal artery, RP renal pelvis, U ureter, hollow arrow marks extrarenal branching of the renal artery into segmental arteries, bold arrow shows formation of the renal vein from segmental veins
the structures lying from lateral to medial side were inferior renal artery, renal pelvis and superior and middle renal arteries. The posterior surface of this kidney was flat with deep groove on lateral border. In this case, kidney was supplied by three renal arteries. Superior renal artery originated from lateral aspect of aorta 2.5 cm above bifurcation of aorta. Near the medial border
123
of the kidney, superior renal artery divided into two branches: one entering the anterior and other posterior surface of kidney near upper pole. The middle renal artery was largest among three and it originated from the ventral aspect of aorta 1.5 cm above bifurcation of aorta. It entered the kidney approximately in the middle of hilum. The inferior renal artery, longest in course, took origin from
Surg Radiol Anat
right common iliac artery 1 cm below aortic bifurcation. It curved around lower most calyx before entering the kidney near lateral border. Renal veins accompanied renal arteries. Case 2 A 50-year male died of hypovolemic shock following road traffic accident. He had no previous history of renal disease. On routine cadaveric dissection, both right and left kidney were normally placed. Right kidney measured 10.5 9 5.5 9 3 cm. The hilum was elliptical and elongated; and it was on posteromedial aspect of the kidney. The renal pelvis and four major calyces were lying outside the renal parenchyma. The extrarenal lengths of four calyces were 3, 1, 1 and 0.5, respectively (Fig. 2). At hilum, the structures lying from anterior to posterior were renal artery, renal vein and renal pelvis. There was no gross evidence of hydronephrosis. There was single renal artery originating from aorta, which divided into four segmental arteries at the hilum. The segmental veins accompanied segmental arteries which formed single renal vein draining into IVC. The anterior surface of the kidney was flat. The left kidney was normal in shape and position.
Discussion Extrarenal calyces are among the rarest anomalies of the renal collecting system. This anomaly was first described in 1925 by Eisendrath [3] and reported sporadically by few authors [2, 9]. This entity was again described and reviewed by Malament [4]. There are only 20 cases reported so far [8]. Extrarenal calyces are reported more commonly on left side than on right side. The left side was involved twice as frequently as the right [2]. In our series, both cases of extrarenal calyces were of right-sided kidney. Kidney with extrarenal calyces is usually associated with other anomalies such as bifid ureter, renal ectopia, horseshoe kidney and renal dysgenesis, etc [4, 5]. Out of all the cases reported so far, majority had associated ectopic kidney [1, 7]. In case 1, extrarenal calyces were associated with ectopic kidney and showed features of non-rotation (as hilum was facing anteriorly). During fetal development, as the kidney ascents, it is accompanied by rotation. Therefore, unaccented kidney (ectopic kidney) is usually associated with varied degrees of non-rotation. Ectopic kidneys with associated variations in vascular supply are not common. During fetal life, as kidneys ascent from pelvis to posterior abdominal wall, they are supplied by segmental mesonephric arteries at different levels. In ectopia, unaccented kidney retains the vascular pattern corresponding to the developmental stage at which their ascent is arrested. In case 1 of extrarenal calyces with renal
ectopia, there were three renal arteries. The superior and middle renal arteries took origin from aorta at a level lower than normal origin and inferior renal artery originated from common iliac artery. Some significant differences are apparent in these two cases of extrarenal calyces: case 1 = ectopic kidney, multiple arteries, deep renal grooves, very long calyces (twice longer than in case 2) and narrow renal pelvis. Case 2 = orthotopic kidney, normal vascularisation, no external grooves, normal calyceal length, normal wideness of the renal pelvis. These differences might indicate different mechanism at play in each of these two cases. The exact cause of extrarenal calyces is not clear. It has been hypothesized that this anomaly could be due to a disparity resulting from slow development of metanephric tissue and to a relatively rapid development of ureteric bud. The slow development of metanephric tissue could delay its attachment to the collecting system, leading to development of first- and second-order collecting system outside the renal parenchyma. Conversely, with the rapid development of ureteric bud, calyceal system could well develop prior to its coalescence with the nephrogenic mass [1, 4]. This might be the possible mechanism for mal development in the case 2. It is also hypothesized that failure of ureteric bud to indent the nephrogenic mass fails to provide stimulus for rotation and ascent, accounting for the association of extrarenal calyces with renal ectopia and non-rotation [1]. This pathogenesis might have led to the renal development in the case 1. The diagnosis of this congenital anomaly is usually made when clinical symptoms warrant detailed investigations or incidentally when explored for associated disease. The preoperative diagnosis of this anomaly is usually difficult. Plain radiography and ultrasonography are not of much significance. Excretory urography provides good anatomic information about the collecting system. Diagnosis may be made when renal pelvis appears to be situated outside the renal shadow and calyces extend to kidney with incurvation resembling the ‘‘prongs of a small hand garden rake’’ [4]. The extrarenal calyces being unsupported are easily distended on retrograde pyelography, thus may create a false impression of hydronephrosis. It may be concluded that knowledge of this anomaly can help the radiologists in making a preoperative diagnosis of this entity and can prevent wrong diagnosis of hydronephrosis on retrograde pyelography. The awareness of this entity among surgeons can prevent inadvertent injury to extrarenal collecting system during surgery. Conflict of interest of interest.
The authors declare that they have no conflict
Ethical standards The experiments comply with the current laws of the country in which they were performed.
123
Surg Radiol Anat
References 1. Dretler SP, Pfister R, Hendren WH (1970) Extrarenal calyces in the ectopic kidney. J Urol 103(4):406 2. Dunn GP, Gibson TE (1951) Extrarenal calyces. Urol Cutan Rev 55:259–260 3. Eisendrath DN (1925) Report of a case of hydronephrosis in kidney with extrarenal calyces. J Urol 13:51–53 4. Malament M, Schwartz B, Nagamatsu GR (1961) Extrarenal calyces: their relationship to renal disease. Am J Roentgenol Radium Ther Nucl Med 86:823–824 5. Mohanty C, Ray B, Samaratunga U et al (2002) Horseshoe kidney with extrarenal calyces: a case report. J Anat Soc India 51:57–59
123
6. Nataraju G, Nandeesh BN, Gayathri MN (2009) Extrarenal calyces: a rare anomaly of the renal collecting system. Indian J Pathol Microbiol 52(3):368–369 7. Rao DV, Sharma SK, Rao MS et al (1972) Extrarenal calyces with complications: a case report. Aust N Z J Surg 42(2):178–179 8. Taha SA, Hashish MH, Eldarawany HM, Barakat AE, Al-Zahrani AA (2006) Renal dysplasia with extrarenal calyces. Saudi Med J 27(3):392–394 9. Vessen LL (1933) Extrarenal calyces. J Urol 30:487–488 10. Zivkovic D, Varga J, Grebeldinger S, Borisev V (2005) Ureteral triplication: a case report. Med Preg 58:592–595
