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Supernumerary kidney with pelvic communication and a single ureter

Authors:
66 Radiol Bras. 2018 Jan/Fev;51(1):58–68
Letters to the Editor
Dear Editor,
A 40-year-old female patient presented with diffuse abdomi-
nal pain after cholecystectomy with biliary tract exploration for
choledocholithiasis and underwent computed tomography (CT)
of the abdomen for better evaluation. The patient presented with
no other comorbidities and was not taking any medications. The
CT of the abdomen was performed with water-soluble iodinated
contrast medium and three-dimensional (3D) reconstruction
(Figures 1A, 1C, and 1D). In addition to liquid collections sug-
gestive of biloma, CT revealed a distinct, encapsulated reniform
parenchymal mass, anteriorly and near the lower pole of the
right kidney, with a rotational anomaly. Subsequent magnetic
resonance imaging of the urinary tract also demonstrated pelvic
communication between the ipsilateral renal masses and a single
ureter (Figure 1B).
Congenital anomalies of the urinary tract have been the ob-
ject of recent studies in the radiology literature of Brazil(1–3). A
supernumerary kidney is a rare congenital anomaly of the urinary
Supernumerary kidney with pelvic communication and a single ureter tract, fewer than 100 cases having been documented in the lit-
erature, with no difference between the genders and preferential
occurrence on the left side. Because of its rarity, it typically goes
undiagnosed until the fourth decade of life(4,5). A supernumerary
kidney has its own capsule, as well as its own blood supply, and
can be totally separate from the ipsilateral kidney or attached to
it by brous tissue or a parenchymal bridge. In general, the sum
of the volume of ipsilateral fragments is equal to or greater than
that of a normal kidney. The blood vessels that supply the super-
numerary kidney typically originate from the aorta, and drainage
is via the inferior vena cava(6,7).
The embryological basis for the occurrence of a supernu-
merary kidney has not been fully elucidated. One of the main
theories is that there is complete duplication of the ureteral bud,
with independent penetration into the metanephric blastema,
which develops and divides into two kidneys. Another theory is
that there are two independent ureteral buds that penetrate the
metanephric blastema, which then divides(7). It is believed that a
supernumerary kidney with a ureter that has its own insertion site
in the bladder reects an initial division of the mesenchyma be-
Figure 1. A: 3D reconstruction of a CT scan
of the abdomen (excretory phase) showing
a normal left kidney and a supernumerary
kidney in a caudal position and anterior to
the right kidney, with pelvic communication
between them. B: T2-weighted fat-saturated
enhanced fast gradient-recalled echo mag-
netic resonance imaging sequence (excre-
tory phase), with 3D coronal reconstruction,
showing pelvic communication between the
normal right kidney and the supernumerary
kidney, with a single ureter. C,D: Coronal and
sagittal reconstructions of a CT scan of the
abdomen (excretory phase), showing a nor-
mal left kidney, and a distinct and encapsu-
lated reniform parenchymal mass, caudal
and anterior to the right kidney, consistent
with a supernumerary kidney, connected by
a parenchymal bridge with pelvic communi-
cation between the two.
A B
C D
67
Radiol Bras. 2018 Jan/Fev;51(1):58–68
Letters to the Editor
http://dx.doi.org/10.1590/0100-3984.2016.0094
Renata Mendes da Silva1, Jorge Chaib Neto2, Moaci Ferreira
de Morais Júnior2
1. Hospital Universitário da Universidade Federal do Piauí (HU-UFPI), Teresina,
PI, Brazil. 2. Universidade Federal do Piauí (UFPI), Teresina, PI, Brazil. Mailing
address: Dra. Renata Mendes da Silva. Hospital Universitário da Universidade
Federal do Piauí – Radiologia. Campus Universitário Ministro Petrônio Portela,
SG 07, s/n, Ininga. Teresina, PI, Brazil, 64049-550. E-mail: renatamendesa20@
hotmail.com.
fore insertion and branching of the ureteral bud. A supernumer-
ary kidney with a ureter that fuses with that of the normal kidney
probably reects late division of the metanephric mesenchyma(7).
A supernumerary kidney can present as a palpable abdomi-
nal mass, with or without symptomatic nephrolithiasis, hydrone-
phrosis, upper urinary tract infection, or renal tumors. However,
it is typically asymptomatic and does not affect renal function.
Therefore, they are never diagnosed or discovered incidentally(5).
REFERENCES
1. Shigueoka DC. Anatomic variations of the renal arteries, as characterized
by computed tomography angiography: rule or exception? Its usefulness
in surgical plannning. Radiol Bras. 2016;49(4):vii–viii.
2. Mello Júnior CF, Araujo Neto SA, Carvalho Junior AM, et al. Multide-
tector computed tomography angiography of the renal arteries: normal
anatomy and its variations. Radiol Bras. 2016;49:190–5.
3. Silva RM, Morais Júnior MF, Mont’Alverne Filho FE. Pancake kidney
with cysts and a single ureter. Radiol Bras. 2016;49:127–8.
4. Sureka B, Mittal MK, Mittal A, et al. Supernumerary kidneys – a rare
anatomic variant. Surg Radiol Anat. 2014;36:199–202.
5. Suresh J, Gnanasekaran N, Dev B. Fused supernumerary kidney. Radiol
Case Reports. 2011;6:552.
6. Maranhão CP, Miranda CM, Santos CJ, et al. Congenital upper uri-
nary tract abnormalities: new images of the same diseases. Radiol Bras.
2013;46:43–50.
7. Favorito LA, Morais AR. Evaluation of supernumerary kidney with fusion
using magnetic resonance image. Int Braz J Urol. 2012;38:428–9.
Cricoid and cervical osteophytes causing dysphagia: an extremely
rare and interesting case
Dear Editor,
A 54-year-old male presented to our department with a two-
month history of nonprogressive dysphagia to solids and irrita-
tion in the neck. Physical examination and laboratory ndings
were unremarkable. Soft tissue X-ray of the neck, in lateral view,
revealed anterior bridging osteophytes at the C5-C6 level and
an elongated osteophyte in the region of the cricoid cartilage
(Figure 1A). An axial computed tomography (CT) scan showed
the formation of a spur, 2 mm in diameter, extending from the
cricoid cartilage (Figure 1C). Sagittal reconstruction revealed a
cricoid osteophyte extending 9 mm caudally at the C5-C6 level
(Figure 1D). Barium swallow revealed smooth extrinsic indenta-
tion in the esophagus at the level of osteophytes (Figure 1B). The
difculty in swallowing was attributed to the compression of the
esophagus by the cricoid and cervical osteophytes.
Figure 1. A: Soft tissue X-ray of the neck,
in lateral view, showing large anterior os-
teophytes (white arrow) of the C5 and C6
vertebral bodies and an elongated cricoid
osteophyte (black arrow). B: Barium swal-
low revealing a smooth extrinsic indenta-
tion in the esophagus at the level of the
osteophyte formation (arrow). C: Axial CT
scan showing an osteophyte arising from
the cricoid cartilage (arrow). D: Sagittal
reconstructed CT images showing an elon-
gated cricoid osteophyte caudally (arrow)
at the C5-C6 level.
°
°
A B
C D
±
°
... It is important to distinguish a supernumerary kidney from the more typical duplex kidney, which is characterized by two pelvicalyceal systems connected by a single ureter or double ureter (9). A parenchymal bridge or fibrous tissue may connect a supernumerary kidney to the ipsilateral kidney, or it may be completely detached, with its own blood supply and capsule (10). A supernumerary kidney is often functional and typically smaller than the native kidney (11). ...
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A supernumerary kidney is an extremely rare congenital renal anomaly that is characterized by the presence of one or more extra kidneys. Unilateral cases occur more commonly on the left side. Reporting such uncommon anomalies is important for several reasons, such as improving diagnosis and treatment, educating clinicians and radiologists about the identification and treatment of supernumerary kidneys, and comparing the case to existing literature to highlight similarities and differences in presentation, management, or outcomes. A 35-year-old male patient presented to our hospital in Addis Ababa, Ethiopia, with left lower flank pain. His blood pressure was elevated during the initial visit; however, the results of the physical examination and laboratory investigations were unremarkable. Abdominopelvic ultrasound and computed tomographic (CT) urography confirmed the diagnosis of a left-sided supernumerary kidney, with no associated abnormalities. In such cases, the diagnosis of a supernumerary kidney is made using an abdominal ultrasound scan, intravenous urography (IVU), CT urography, and magnetic resonance imaging (MRI). Treatment depends on the patient’s symptoms. Asymptomatic cases must be followed up regularly. If a supernumerary kidney is nonfunctional or associated with other abnormalities, a nephrectomy is indicated. We treated our patient with adequate analgesia and scheduled a follow-up.
... A duplex kidney is a common differential diagnosis, which may not have a separate blood supply and capsule. 1,5,6 In the index case, the accessory kidney was partially fused with the native left kidney with a distinct collecting system uniting at the common renal pelvis and a separate blood supply. ...
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Introduction A supernumerary kidney is an extremely rare congenital anomaly, defined as the presence of one or more extra kidneys. Thus far, there have been less than 100 cases reported in the medical literature. It has its capsule, vascular supply, and collecting system. It frequently causes diagnostic challenges in clinical practice. The supernumerary kidney can be symptomatic due to the presence of stone. Case Presentation We present a case of a 19-year-old male patient who came to our clinic with the complaint of abdominal pain. On computed tomography urography (CTU), he was found to have a caudally located left fused supernumerary kidney with a separate vascular supply. Both left kidneys had a separately draining calyceal systems uniting at the left renal pelvis and drained by a single ureter. Multiple left renal stones (largest measures 4cm x 2.2cm) in both kidneys were also seen. The stones were removed surgically by doing pyelolithotomy and radial nephrolithotomy. The patient was doing well during follow-up visits with the improvement of abdominal pain. Conclusion Supernumerary kidney is a very rare congenital renal anomaly. This case is even unique, because of the fused supernumerary kidney and the presence of a single left renal pelvis and ureter. Imaging is very essential for planning surgical intervention. Stones in such kidneys can be managed with nephrolithotomy and/or pyelolithotomy.
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Supernumerary kidneys, also known as accessory kidneys, refer to the presence of more than two kidneys. It is a rare congenital abnormality of the urinary system with only a few cases reported so far in literature. The extra kidney commonly has its own collecting system, blood supply, and well-defined encapsulated tissue. It may or may not be fused to the other kidneys by fibrous tissue or a parenchymal bridge. Imaging for vague abdominal symptoms may result in an incidental finding of the rare anatomical variant which may indicate an adjustment of routine physical activities to avoid renal trauma, as well as relevant considerations for surgical planning. We present a 62-year-old woman who presented with vague abdominal pains. Findings on physical examination were unremarkable. Her abdominal ultrasound scan showed two kidneys of about the same size fused together. Computed tomography urography showed two fused renal tissues of nearly same size on the left. The accessory kidney is more medial, slightly cranial. The native kidney is more lateral and more caudal. The native and accessory kidneys had only one blood supply, venous drainage, and a single ureter. As at the time of reporting, the patient has not received any intervention because there was no remarkable symptom noted. This case is rare and unique, in that it is a fused supernumerary kidney seen at the age of 62 and has a single blood supply and ureter. Imaging for vague symptoms can result in an incidental finding of a rare anatomical variant. It is also very essential for planning surgical intervention if need be.
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