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Horseshoe Kidney in Children
Vol. 108, August Printed in U.S.A.
THE JOURNAL OF UROLOGY
Copyright © 1972 by The Williams & Wilkins Co.
HORSESHOE KIDNEY IN CHILDREN JOSEPH W. SEGURA, PANAYOTIS P. KELALIS
AND
EDMUND C. BURKE
From the ililayo Clinic ancl Mayo Foundation, Rochester, Minnesota
Hydronephrosis, infection and renal calculi are recognized complications of horseshoe kidney. However, the incidence of associated urinary tract abnormalities as well as abnormalities of other organ systems is less well known. The higher incidence at autopsy of horseshoe kidney in children than adults1 suggests that an increased risk is associated with horseshoe kidney in children. Our review was undertaken in an attempt to characterize the child with horseshoe kidney and to define the implications of the diagnosis of horseshoe kidney in the pediatric patient. Records were reviewed of all children 15 years of age or younger seen at the JVIayo Clinic from 1935 to 1970 in whom horseshoe kidney was diagnosed. There were 34 patients: 18 boys and 16 girls. Horseshoe kidney was diagnosed by roentgenographic findings in 31 cases and at autopsy in 3 cases. FINDINGS
Three patients had horseshoe kidney associated with severe congenital anomalies not only of the urinary tract but also of other organ systems (table 1). Two of these children died shortly after birth of complications related to their anomalies. The third child died of respiratory insufficiency at 2 months of age. The horseshoe configuration, itself, had no direct bearing on death. Two of the 3 patients had renal cystic dysplasia. Thirty-one patients (16 boys and 15 girls) had horseshoe kidney diagnosed by excretory urography (IVP). These children ranged in age from 2 months to 15 years and averaged 6% years at the time of diagnosis. Most presenting symptoms were associated with urinary tract infections (table 2). Three patients underwent examination because of an abdominal mass and 6 had horseshoe kidney discovered during evaluation for unrelated problems. More than a third of these patients were symptomatic during their first year of life; by the end of the third year, more than half had symptoms that led to the diagnosis. Abnormalities in other systems were revealed through urologic and general evaluations (table 3). Only 7 patients had no additional abnormalities. Abnormalities of skeletal and cardiovascular systems were relatively frequent and generally were mild. These included anomalous ribs and vertebrae as Accepted for publication November 24, 1971. Read at annual meeting of North Central Section, American Urological Association, Detroit, Michigan, September 22-25, 1971. 1 Campbell, M. F. and Harrison, J. H.: Urology, 3rd ed. Philadelphia: W. B. Saunders Co., 1970.
well as heart murmurs. One child died of an unsuspected ruptured abdominal aortic aneurysm at the age of 12 years; this was years after horseshoe kidney was diagnosed. Gastrointestinal findings were of major significance and included imperforate anus in 1 case and duplication of the rectosigmoid with Hirschsprung's disease in another. Half of the children had changes elsewhere in the urinary tract. Of the 10 patients with normal IVPs, 3 had reflux and 2 had anomalies of other organ systems (table 4). Most of the abnormal IVPs revealed changes that are frequently associated with horseshoe kidney, such as pyelocaliectasis. Only 12 children underwent cystoscopy but significant anatomic abnormalities were noted in two-thirds of these. Cine-cystourethrography produced a high yield of positive findings as did retrograde cystography. Despite presenting complaints indicative of urinary tract infections, only 3 patients had significant bacteriuria. One-third of the children had microhematuria. Significant anatomic abnormalities were found in the urinary tract of some patients (table 5). Eight of the 10 children who underwent cystography had reflux. A paraureteral diverticulum was associated with 1 ureter with reflux. There were also several less significant urologic findings. Twelve patients in our series were managed conservatively. Problems in this group ranged from reflux to associated anomalies of other organ systems. Two patients had completely negative diagnostic studies. Seventeen of the 31 children underwent surgical procedures: 12 underwent operations confined to the urinary tract while 5 underwent operations on other organ systems. If the 2 patients who were operated on prior to their arrival at our clinic and the 1 patient who was operated on at another institution since are included, then 15 patients (48 per cent) in our series required operative intervention of the urinary tract. Separation of the 2 halves of the horseshoe kidney combined with a plastic procedure on the renal pelvis and partial nephrectomy was the most frequently performed surgical procedure (table 6). Reflux was present in 3 children who underwent this procedure and changes in the horseshoe kidney which necessitated operation were consistent with those frequently associated with refiux. Operations at other sites in the urinary tract were directed at congenital abnormalities of the ureterovesical Junction (table 6). Three children underwent exploratory laparotomy for abdominal masses (table 7). Two had neuroblastoma and the third had a lymphoblastic lymphoma. Despite efforts at surgical excision, all died within months of the diagnosis. Three patients were lost to followup. More than
333
334
SEGURA, KELALIS AND BURKE
TABLE
1. Major defects of patients who cliecl of con-
TABLE
genital anomalies by 2 months of age Urologic Cystic dysplasia Cystic dysplasia (It. half) None
TABLE
Cardiac
Gastrointestinal
No.
Other
Major defects
T-E fistula
None
Major defects
None
Turner's syndrome
Major defects
None
Edwards' syn(tridrome somy 18)
2. Presenting symptoms of 31 children with horseshoe kidney No.(%) Urinary tract infection Abdominal mass Gross hematuria Abdominal pain Other
16 3 3 3 6
Total
31 (100)
(52) (10) (10) (10) (18)
Followed only Surgery: On horseshoe kidney a1one: Symphysiotomy or symphysiectomy, 7 Nephropexy, 4 Pyeloplasty, 4 Partial nephrectomy, 6 Other urinary tract sites: U reteroneocystostomy: U nilatera1, 1 Bilateral, 2 Excision of ureterocele, 1 Miscellaneous: Abdominal exploration, 3 Colon resection, 1 Cardiac operation, 1
12 17
Total
29
* Six
10*
4t
patients required more than 1 operation.
t Two patients underwent operation on horseshoe kidney and at other urinary tract site.
TABLE TABLE
6. Management in 29 cases of horseshoe kidney in children
7. Location and type of tumor in 3 fatal cases
3. Additional abnormalities in 31 children with horseshoe kidney
of horses hoe kiclney in children Tumor
Age (yrs.)
Symptom
Site
No.(%) Urologic (additional) Skeletal Cardiovascular Gastrointestinal Other None Tumors
TAnu~
N euroblastoma
16 8 8 4 6
(52) (26) (26) (13) (19) 7 (23) 3 (10)
4. Results of urologic evaluation in 31 children
N euroblastoma
Lt. half of horseshoe kidney Retroperitoneum
Lymphoblastic lymphoma
Small bowel mesentery
TABLE
with horseshoe kiclney No. IVP Cystoscopy Cine-cystography Retrograde cystography Urine culture
TABLE
31 12 5 5 23
21 8
4 0 20
5. Major urinary tract abnormalities in 31 children with horseshoe kidney
4}2
Abdominal pain, vomiting Abdominal mass
2}1
5
8. Results of followup in 28 cases* of horseshoe kidney in children Duration (yrs.)
Normal Abnormal 10
Abdominal pain
Result
No.(%)
Alive and well Urologic sequelae Other sequelae Died
15 (54) (21) 2 (7) 5 (18)
Total
28 (100)
Mean (range) 8 (0. 2-26) 6. 7 (3-19) 4 (1.3-7)
* Three children lost to followup.
Ko. TABLE
Reflux: Unilateral Bilateral Urethral valves Previous testicular torsion Congenital urethrorectal fistula U reterocele Complete ureteral duplication: Unilateral Bilateral Para-ureteral diverticulum Undescended testes (bilateral) Coronal hypospadias
9. Results by management in 21 cases of horseshoe kidney in children Urinary Tract Operation
Fo11owed Only
No.(%)
No.(%)
Alive and well U rologic sequelae Other sequelae Died
10 (83) 2 (17) 0
4 3 1 1
Total
12 (100)
* Three children lost
to followup.
0
(45)
(33) (11) (11)
9* (100)
HORSESHOE KIDNEY IN CHILDREN
335
Fm. 1. Roentgenogram shows association of changes which could be attributable to bilateral ureteropelvic obstruction and bilateral reflux.
Fm. 2. A, roentgenogram shows association of ureterocele and horseshoe kidney. B, gross specimen shows resected horseshoe kidney and ureterocele.
336
SEGURA, KELALIS AND BURKE
half of the remammg 28 children were well when last seen (table 8). These included 10 of 12 children who underwent operation as well as 4 of 9 who were managed conservatively (table 9). Six of the 28 patients had persistent urologic problems such as continued symptoms, decreased renal function or deterioration, as demonstrated by IVP. Five children died: 3 of tumor (table 7), 1 of an unsuspected ruptured abdominal aortic aneurysm and 1 of complications after a cardiac operation. COMMEXT
Patients with horseshoe kidney may be classified into 2 groups: those with associated severe congenital anomalies (who are either stillborn or die of their defects shortly after birth) and those in whom other abnormalities also may be present and the horseshoe kidney is usually diagnosed roentgenographically. In the first group horseshoe kidney is usually an associated finding at autopsy; this is corroborated by a large autopsy serie:c; of children by Zondek and Zondek2 v>'ho found that only 5 per cent had died of horseshoe kidney. Symptoms that lead to diagnosis begin early in life and generally are related to urinary tract infection. Significant bacteriuria is not likely to be demonstrable, at least initially, and microhematuria will be frequent. The symptoms or findings of an associated abnormality may coexist but these usually will not lead to diagnosis. The horseshoe configuration results from fusion of the nephrogenic blastema during the fourth week of fetal life. The factors responsible remain uncertain, although fusion may occur when the developing umbilical arteries bring the 2 blastemas into apposition in the fetal pelvis.1 That more than mechanical factors alone may be involved is suggested by the high incidence of other abnormalities in the urinary tract and the consistent, widespread presence of anomalies in other organs. Some teratogenic factor operating early in embryonic development, as suggested by Neidhardt and associates,3 may be responsible for the associated widespread anomalies. We believe it is of particular significance that vesicoureteral reflux was found in 80 per cent of patients so investigated and reflects aberrations simultaneously evident at both ends of the ureteral bud and which are not necessarily interrelated. Such reflux may be responsible for the frequent diagnosis in the past of apparent ureteropelvic obstruction, resulting from the regurgitated column of urine to the renal pelvis. Thus, vesicoureteral reflux must be excluded in all patients in whom horseshoe kidney is demonstrated roentgenographi2 Zondek, L. H. and Zondek, T.: Horseshoe kidney and associated congenital malformations. Urol. Int., 18: 347, 1964. 3 Neidhardt, J. H., Bouchet, A., Morin, A., Theoleyre, J. and Felman, D.: Apropos des malformations associees a certaines anomalies et agenesies renales. Lyon Med., 217: 1582, 1967.
cally. Illustrative of such a situation is the patient who has upper urinary tract changes that could be attributable to obstruction of the ureteropelvic junction but who has bilateral reflux (fig. 1). Included may be other examples of aberrations of the ureteral bud with anomalies at both ends, the association of horseshoe kidney with ureterocele (fig. 2), complete ureteral duplication and possibly the presence of dysplastic elements within the kidney itself. Whether anomalies occur more frequently in patients with malignancy has been debated. Kobayashi and associates4 noted that 35 per cent of patients with neuroblastoma had anomalies. Recently, Derry and associates 5 found no significant association between malformation and neoplasia. We found only 1 case of neuroblastoma associated with horseshoe kidney. 6 Although the relatively high incidence of malignancy noted in that study may be coincidental, it is a surprising and unexplained phenomenon. Two of every 3 children with horseshoe kidney will require some operative procedure. That this will materially decrease morbidity is reflected in the fact that patients managed conservatively in our review were doing less well than those treated surgically. However, mortality was not related to the horseshoe kidney or to the usual problems present in horseshoe kidney. The study suggests that the higher mortality rate associated with horseshoe kidney in children, compared to the adult, is explicable on the basis of abnormalities of other organ systems. We believe that the diagnosis of horseshoe kidney in the pediatric patient should initiate a thorough urologic evaluation, including cine-cystography and cystoscopy. Further, an accurate definition of such anomalies as may be present in other organ systems is imperative. SUMMARY
A review of the records of 34 children with horseshoe kidney revealed a high incidence of associated abnormalities of the urinary tract as well as of other organ systems. Eight of the 10 children investigated had vesicoureteral reflux. Two-thirds of the children with horseshoe kidney required some surgical procedure. The higher mortality rate associated with horseshoe kidney in children as compared to adults is explained on the basis of abnormalities in other organ systems. All children with horseshoe kidney should have a complete urologic examination and an accurate definition of any abnormality in other organ systems. 4 Kobayashi, N., Furukawa, T. and Takatsu, T.: Congenital anomalies in children with malignancy. Paediat. Univ. Tokyo, 16: 31, 1968. 5 Berry, C. L., Keeling, J. and Hilton, C.: Coincidence of congenital malformation and embryonic tumours of childhood. Arch. Dis. Child., 45: 229, 1970. 6 Taylor, J.M., Russo, P. E. and Jacobson, M. E.: N euroblastoma in a case of horseshoe kidney. J. Urol., 70: 864, 1953.
THE JOURNAL OF UROLOGY
Copyright © 1972 by The Williams & Wilkins Co.
HORSESHOE KIDNEY IN CHILDREN JOSEPH W. SEGURA, PANAYOTIS P. KELALIS
AND
EDMUND C. BURKE
From the ililayo Clinic ancl Mayo Foundation, Rochester, Minnesota
Hydronephrosis, infection and renal calculi are recognized complications of horseshoe kidney. However, the incidence of associated urinary tract abnormalities as well as abnormalities of other organ systems is less well known. The higher incidence at autopsy of horseshoe kidney in children than adults1 suggests that an increased risk is associated with horseshoe kidney in children. Our review was undertaken in an attempt to characterize the child with horseshoe kidney and to define the implications of the diagnosis of horseshoe kidney in the pediatric patient. Records were reviewed of all children 15 years of age or younger seen at the JVIayo Clinic from 1935 to 1970 in whom horseshoe kidney was diagnosed. There were 34 patients: 18 boys and 16 girls. Horseshoe kidney was diagnosed by roentgenographic findings in 31 cases and at autopsy in 3 cases. FINDINGS
Three patients had horseshoe kidney associated with severe congenital anomalies not only of the urinary tract but also of other organ systems (table 1). Two of these children died shortly after birth of complications related to their anomalies. The third child died of respiratory insufficiency at 2 months of age. The horseshoe configuration, itself, had no direct bearing on death. Two of the 3 patients had renal cystic dysplasia. Thirty-one patients (16 boys and 15 girls) had horseshoe kidney diagnosed by excretory urography (IVP). These children ranged in age from 2 months to 15 years and averaged 6% years at the time of diagnosis. Most presenting symptoms were associated with urinary tract infections (table 2). Three patients underwent examination because of an abdominal mass and 6 had horseshoe kidney discovered during evaluation for unrelated problems. More than a third of these patients were symptomatic during their first year of life; by the end of the third year, more than half had symptoms that led to the diagnosis. Abnormalities in other systems were revealed through urologic and general evaluations (table 3). Only 7 patients had no additional abnormalities. Abnormalities of skeletal and cardiovascular systems were relatively frequent and generally were mild. These included anomalous ribs and vertebrae as Accepted for publication November 24, 1971. Read at annual meeting of North Central Section, American Urological Association, Detroit, Michigan, September 22-25, 1971. 1 Campbell, M. F. and Harrison, J. H.: Urology, 3rd ed. Philadelphia: W. B. Saunders Co., 1970.
well as heart murmurs. One child died of an unsuspected ruptured abdominal aortic aneurysm at the age of 12 years; this was years after horseshoe kidney was diagnosed. Gastrointestinal findings were of major significance and included imperforate anus in 1 case and duplication of the rectosigmoid with Hirschsprung's disease in another. Half of the children had changes elsewhere in the urinary tract. Of the 10 patients with normal IVPs, 3 had reflux and 2 had anomalies of other organ systems (table 4). Most of the abnormal IVPs revealed changes that are frequently associated with horseshoe kidney, such as pyelocaliectasis. Only 12 children underwent cystoscopy but significant anatomic abnormalities were noted in two-thirds of these. Cine-cystourethrography produced a high yield of positive findings as did retrograde cystography. Despite presenting complaints indicative of urinary tract infections, only 3 patients had significant bacteriuria. One-third of the children had microhematuria. Significant anatomic abnormalities were found in the urinary tract of some patients (table 5). Eight of the 10 children who underwent cystography had reflux. A paraureteral diverticulum was associated with 1 ureter with reflux. There were also several less significant urologic findings. Twelve patients in our series were managed conservatively. Problems in this group ranged from reflux to associated anomalies of other organ systems. Two patients had completely negative diagnostic studies. Seventeen of the 31 children underwent surgical procedures: 12 underwent operations confined to the urinary tract while 5 underwent operations on other organ systems. If the 2 patients who were operated on prior to their arrival at our clinic and the 1 patient who was operated on at another institution since are included, then 15 patients (48 per cent) in our series required operative intervention of the urinary tract. Separation of the 2 halves of the horseshoe kidney combined with a plastic procedure on the renal pelvis and partial nephrectomy was the most frequently performed surgical procedure (table 6). Reflux was present in 3 children who underwent this procedure and changes in the horseshoe kidney which necessitated operation were consistent with those frequently associated with refiux. Operations at other sites in the urinary tract were directed at congenital abnormalities of the ureterovesical Junction (table 6). Three children underwent exploratory laparotomy for abdominal masses (table 7). Two had neuroblastoma and the third had a lymphoblastic lymphoma. Despite efforts at surgical excision, all died within months of the diagnosis. Three patients were lost to followup. More than
333
334
SEGURA, KELALIS AND BURKE
TABLE
1. Major defects of patients who cliecl of con-
TABLE
genital anomalies by 2 months of age Urologic Cystic dysplasia Cystic dysplasia (It. half) None
TABLE
Cardiac
Gastrointestinal
No.
Other
Major defects
T-E fistula
None
Major defects
None
Turner's syndrome
Major defects
None
Edwards' syn(tridrome somy 18)
2. Presenting symptoms of 31 children with horseshoe kidney No.(%) Urinary tract infection Abdominal mass Gross hematuria Abdominal pain Other
16 3 3 3 6
Total
31 (100)
(52) (10) (10) (10) (18)
Followed only Surgery: On horseshoe kidney a1one: Symphysiotomy or symphysiectomy, 7 Nephropexy, 4 Pyeloplasty, 4 Partial nephrectomy, 6 Other urinary tract sites: U reteroneocystostomy: U nilatera1, 1 Bilateral, 2 Excision of ureterocele, 1 Miscellaneous: Abdominal exploration, 3 Colon resection, 1 Cardiac operation, 1
12 17
Total
29
* Six
10*
4t
patients required more than 1 operation.
t Two patients underwent operation on horseshoe kidney and at other urinary tract site.
TABLE TABLE
6. Management in 29 cases of horseshoe kidney in children
7. Location and type of tumor in 3 fatal cases
3. Additional abnormalities in 31 children with horseshoe kidney
of horses hoe kiclney in children Tumor
Age (yrs.)
Symptom
Site
No.(%) Urologic (additional) Skeletal Cardiovascular Gastrointestinal Other None Tumors
TAnu~
N euroblastoma
16 8 8 4 6
(52) (26) (26) (13) (19) 7 (23) 3 (10)
4. Results of urologic evaluation in 31 children
N euroblastoma
Lt. half of horseshoe kidney Retroperitoneum
Lymphoblastic lymphoma
Small bowel mesentery
TABLE
with horseshoe kiclney No. IVP Cystoscopy Cine-cystography Retrograde cystography Urine culture
TABLE
31 12 5 5 23
21 8
4 0 20
5. Major urinary tract abnormalities in 31 children with horseshoe kidney
4}2
Abdominal pain, vomiting Abdominal mass
2}1
5
8. Results of followup in 28 cases* of horseshoe kidney in children Duration (yrs.)
Normal Abnormal 10
Abdominal pain
Result
No.(%)
Alive and well Urologic sequelae Other sequelae Died
15 (54) (21) 2 (7) 5 (18)
Total
28 (100)
Mean (range) 8 (0. 2-26) 6. 7 (3-19) 4 (1.3-7)
* Three children lost to followup.
Ko. TABLE
Reflux: Unilateral Bilateral Urethral valves Previous testicular torsion Congenital urethrorectal fistula U reterocele Complete ureteral duplication: Unilateral Bilateral Para-ureteral diverticulum Undescended testes (bilateral) Coronal hypospadias
9. Results by management in 21 cases of horseshoe kidney in children Urinary Tract Operation
Fo11owed Only
No.(%)
No.(%)
Alive and well U rologic sequelae Other sequelae Died
10 (83) 2 (17) 0
4 3 1 1
Total
12 (100)
* Three children lost
to followup.
0
(45)
(33) (11) (11)
9* (100)
HORSESHOE KIDNEY IN CHILDREN
335
Fm. 1. Roentgenogram shows association of changes which could be attributable to bilateral ureteropelvic obstruction and bilateral reflux.
Fm. 2. A, roentgenogram shows association of ureterocele and horseshoe kidney. B, gross specimen shows resected horseshoe kidney and ureterocele.
336
SEGURA, KELALIS AND BURKE
half of the remammg 28 children were well when last seen (table 8). These included 10 of 12 children who underwent operation as well as 4 of 9 who were managed conservatively (table 9). Six of the 28 patients had persistent urologic problems such as continued symptoms, decreased renal function or deterioration, as demonstrated by IVP. Five children died: 3 of tumor (table 7), 1 of an unsuspected ruptured abdominal aortic aneurysm and 1 of complications after a cardiac operation. COMMEXT
Patients with horseshoe kidney may be classified into 2 groups: those with associated severe congenital anomalies (who are either stillborn or die of their defects shortly after birth) and those in whom other abnormalities also may be present and the horseshoe kidney is usually diagnosed roentgenographically. In the first group horseshoe kidney is usually an associated finding at autopsy; this is corroborated by a large autopsy serie:c; of children by Zondek and Zondek2 v>'ho found that only 5 per cent had died of horseshoe kidney. Symptoms that lead to diagnosis begin early in life and generally are related to urinary tract infection. Significant bacteriuria is not likely to be demonstrable, at least initially, and microhematuria will be frequent. The symptoms or findings of an associated abnormality may coexist but these usually will not lead to diagnosis. The horseshoe configuration results from fusion of the nephrogenic blastema during the fourth week of fetal life. The factors responsible remain uncertain, although fusion may occur when the developing umbilical arteries bring the 2 blastemas into apposition in the fetal pelvis.1 That more than mechanical factors alone may be involved is suggested by the high incidence of other abnormalities in the urinary tract and the consistent, widespread presence of anomalies in other organs. Some teratogenic factor operating early in embryonic development, as suggested by Neidhardt and associates,3 may be responsible for the associated widespread anomalies. We believe it is of particular significance that vesicoureteral reflux was found in 80 per cent of patients so investigated and reflects aberrations simultaneously evident at both ends of the ureteral bud and which are not necessarily interrelated. Such reflux may be responsible for the frequent diagnosis in the past of apparent ureteropelvic obstruction, resulting from the regurgitated column of urine to the renal pelvis. Thus, vesicoureteral reflux must be excluded in all patients in whom horseshoe kidney is demonstrated roentgenographi2 Zondek, L. H. and Zondek, T.: Horseshoe kidney and associated congenital malformations. Urol. Int., 18: 347, 1964. 3 Neidhardt, J. H., Bouchet, A., Morin, A., Theoleyre, J. and Felman, D.: Apropos des malformations associees a certaines anomalies et agenesies renales. Lyon Med., 217: 1582, 1967.
cally. Illustrative of such a situation is the patient who has upper urinary tract changes that could be attributable to obstruction of the ureteropelvic junction but who has bilateral reflux (fig. 1). Included may be other examples of aberrations of the ureteral bud with anomalies at both ends, the association of horseshoe kidney with ureterocele (fig. 2), complete ureteral duplication and possibly the presence of dysplastic elements within the kidney itself. Whether anomalies occur more frequently in patients with malignancy has been debated. Kobayashi and associates4 noted that 35 per cent of patients with neuroblastoma had anomalies. Recently, Derry and associates 5 found no significant association between malformation and neoplasia. We found only 1 case of neuroblastoma associated with horseshoe kidney. 6 Although the relatively high incidence of malignancy noted in that study may be coincidental, it is a surprising and unexplained phenomenon. Two of every 3 children with horseshoe kidney will require some operative procedure. That this will materially decrease morbidity is reflected in the fact that patients managed conservatively in our review were doing less well than those treated surgically. However, mortality was not related to the horseshoe kidney or to the usual problems present in horseshoe kidney. The study suggests that the higher mortality rate associated with horseshoe kidney in children, compared to the adult, is explicable on the basis of abnormalities of other organ systems. We believe that the diagnosis of horseshoe kidney in the pediatric patient should initiate a thorough urologic evaluation, including cine-cystography and cystoscopy. Further, an accurate definition of such anomalies as may be present in other organ systems is imperative. SUMMARY
A review of the records of 34 children with horseshoe kidney revealed a high incidence of associated abnormalities of the urinary tract as well as of other organ systems. Eight of the 10 children investigated had vesicoureteral reflux. Two-thirds of the children with horseshoe kidney required some surgical procedure. The higher mortality rate associated with horseshoe kidney in children as compared to adults is explained on the basis of abnormalities in other organ systems. All children with horseshoe kidney should have a complete urologic examination and an accurate definition of any abnormality in other organ systems. 4 Kobayashi, N., Furukawa, T. and Takatsu, T.: Congenital anomalies in children with malignancy. Paediat. Univ. Tokyo, 16: 31, 1968. 5 Berry, C. L., Keeling, J. and Hilton, C.: Coincidence of congenital malformation and embryonic tumours of childhood. Arch. Dis. Child., 45: 229, 1970. 6 Taylor, J.M., Russo, P. E. and Jacobson, M. E.: N euroblastoma in a case of horseshoe kidney. J. Urol., 70: 864, 1953.