Figure 1
absent kidney on right side
Axial section at level of kidneys showing absent kidney on right
Crossed fused renal ectopia with calculi
SectionUroradiology & genital male imaging
Case TypeClinical Cases
AuthorsSankalp Tripathi, Nabil Kibriya, Nusrat Alam, Fatma Bayam, Richard Sloka
Connected authors
63 years, male
Clinical History
A 63 year old man presented with left loin to groin pain with known crossed fused renal ectopia. Diagnosis of renal colic with urinary tract infection was made. Abdominal CT revealed atrophic left kidney fused to crossed functional right kidney with distal left ureter calculi.
Imaging Findings
A 63 year old male patient was admitted with one week history of worsening left loin pain. The pain was described as “stabbing” and radiating down to the left groin. There was associated nausea, dysuria and intermittent fevers. There was however no haematuria, frequency or prostatic symptoms. The patient was known to have poor renal function with crossed fused renal ectopia on the left.
On examination, he was pyrexial with a temperature of 38.2ºC. His abdomen was soft but was tender in his left renal angle. PR examination was unremarkable.
Following investigation, urinalysis showed 1+ of protein and leucocytes, blood tests revealed a mildly raised WCC of 12.5 with a creatinine of 129 and urea of 3.5. An abdominal ultrasound demonstrated a large single left kidney (>12.5cm) with no evidence of hydronephrosis and absent right kidney.
The patient was clinically diagnosed with renal colic with a possible urinary tract infection and treatment was initiated appropriately.
An abdominal CT followed which revealed a non functional atrophic left kidney fused to crossed functional right kidney. The ureter of left kidney had normal path whearas the ureter of crossed right kidney crossed from left to right to be inserted normally on right. There were calculi seen in distal left ureter.
At this stage, the case was discussed at a multidisciplinary meeting and it was decided ureteroscopy and extraction of the calculus to be attempted as it was presumed cause of the pain.
On examination, he was pyrexial with a temperature of 38.2ºC. His abdomen was soft but was tender in his left renal angle. PR examination was unremarkable.
Following investigation, urinalysis showed 1+ of protein and leucocytes, blood tests revealed a mildly raised WCC of 12.5 with a creatinine of 129 and urea of 3.5. An abdominal ultrasound demonstrated a large single left kidney (>12.5cm) with no evidence of hydronephrosis and absent right kidney.
The patient was clinically diagnosed with renal colic with a possible urinary tract infection and treatment was initiated appropriately.
An abdominal CT followed which revealed a non functional atrophic left kidney fused to crossed functional right kidney. The ureter of left kidney had normal path whearas the ureter of crossed right kidney crossed from left to right to be inserted normally on right. There were calculi seen in distal left ureter.
At this stage, the case was discussed at a multidisciplinary meeting and it was decided ureteroscopy and extraction of the calculus to be attempted as it was presumed cause of the pain.
Discussion
A normal kidney in an adult in supine position is positioned at the level of L1 or L2 and its medial border is anterior to lateral border so that it forms an angle of 30 degrees with horizontal [2].
Congenital renal anomalies can be classified as 1) anomalies in number, 2) anomalies in size, 3) anomalies in position, 4) anomalies in form, 5) anomalies in structure.
On further classification of anomalies of position they can be further sub-divided into a) anomalies of rotation and b) renal ectopia.
Renal ectopia is a kidney in congenitally abnormal location. Usually these kidneys have an ectopic arterial blood supply. The length of the ureter must adjust itself to the position of the kidney hence intrathoracic kidney has long ureter and pelvic kidney has a small ureter. A differential for renal ectopia is renal ptosis which is an abnormally mobile kidney that drops down in the abdomen when patient is upright. In renal ptosis the ureter is of normal length and renal arteries arise from their normal sites.
Renal ectopia can be a) ipsilateral or b) crossed renal ectopia.
Ipsilateral ectopia is where kidney is on same side as attendant ureter orifice, and can be further divided into cranial (usually intrathoracic) or caudal (below L2) ectopias.
Crossed renal ectopias or contralateral renal ectopias is where kidney is located opposite to its attendant ureteral orifice. These anomalies can occour with fusion, without fusion or in a solitary kidney. In our case it was crossed ectopia with fused atrophic kidney.
These ectopic kidneys are prone for complications. Any disease that may develop in a normal kidney can develop in an ectopic kidney. Ectopic kidneys are more prone to trauma, calculi, and if in pelvis they can obstruct labour and about 50% of these pelvic kidneys have decreased function.
The kidney initially starts to develop opposite future S1 and S2 and ascend to lie opposite L1 or L2 in adult life.
One study showed that ectopia was inherited as an autosomal recessive trait [1]. Renal ectopias have been demonstrated in monozygotic twins suggesting hereditary factor.
Congenital renal anomalies can be classified as 1) anomalies in number, 2) anomalies in size, 3) anomalies in position, 4) anomalies in form, 5) anomalies in structure.
On further classification of anomalies of position they can be further sub-divided into a) anomalies of rotation and b) renal ectopia.
Renal ectopia is a kidney in congenitally abnormal location. Usually these kidneys have an ectopic arterial blood supply. The length of the ureter must adjust itself to the position of the kidney hence intrathoracic kidney has long ureter and pelvic kidney has a small ureter. A differential for renal ectopia is renal ptosis which is an abnormally mobile kidney that drops down in the abdomen when patient is upright. In renal ptosis the ureter is of normal length and renal arteries arise from their normal sites.
Renal ectopia can be a) ipsilateral or b) crossed renal ectopia.
Ipsilateral ectopia is where kidney is on same side as attendant ureter orifice, and can be further divided into cranial (usually intrathoracic) or caudal (below L2) ectopias.
Crossed renal ectopias or contralateral renal ectopias is where kidney is located opposite to its attendant ureteral orifice. These anomalies can occour with fusion, without fusion or in a solitary kidney. In our case it was crossed ectopia with fused atrophic kidney.
These ectopic kidneys are prone for complications. Any disease that may develop in a normal kidney can develop in an ectopic kidney. Ectopic kidneys are more prone to trauma, calculi, and if in pelvis they can obstruct labour and about 50% of these pelvic kidneys have decreased function.
The kidney initially starts to develop opposite future S1 and S2 and ascend to lie opposite L1 or L2 in adult life.
One study showed that ectopia was inherited as an autosomal recessive trait [1]. Renal ectopias have been demonstrated in monozygotic twins suggesting hereditary factor.
Differential Diagnosis List
crossed fused renal ectopia with calculi
Final Diagnosis
crossed fused renal ectopia with calculi
Case information
| URL: | https://www.eurorad.org/case/6910 |
| DOI: | 10.1594/EURORAD/CASE.6910 |
| ISSN: | 1563-4086 |
Figure 2
Coronal image
Coronal image showing no kidney on right and ectopic kidney on left
Figure 3
Axial image
Axial image showing ureter from ectopic kidney crossing midline
Figure 4
Coronal image
Coronal image showing calculi in left ureter
absent kidney on right side
Axial section at level of kidneys showing absent kidney on right
Coronal image
Coronal image showing no kidney on right and ectopic kidney on left
Axial image
Axial image showing ureter from ectopic kidney crossing midline
Coronal image
Coronal image showing calculi in left ureter