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Saudi Journal of Kidney Diseases and Transplantation
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Year : 2019  |  Volume : 30  |  Issue : 2  |  Page : 549-552
A rare case of pancake kidney with glomerulonephritis

1 Department of Nephrology, Sri Ramachandra Institute of Higher Education and Research, Chennai, Tamil Nadu, India
2 Department of Radiology, Sri Ramachandra Institute of Higher Education and Research, Chennai, Tamil Nadu, India

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Date of Submission30-Jan-2018
Date of Decision04-Feb-2018
Date of Acceptance04-Apr-2018
Date of Web Publication23-Apr-2019


Developmental anomalies of the kidney and the urinary tract occur in 3-6 per 1000 live births. Pancake kidney is one of the rarest types of renal ectopia. Urinary system anomalies often coexist with malformations of other organs and systems. We report a case of pancake kidney which was detected incidentally while treating a patient with renal failure and nephrotic syndrome.

How to cite this article:
Mamidi V, Elayaperumal I, Chakola JJ, Venkata Sai P M, Matcha J. A rare case of pancake kidney with glomerulonephritis. Saudi J Kidney Dis Transpl 2019;30:549-52

How to cite this URL:
Mamidi V, Elayaperumal I, Chakola JJ, Venkata Sai P M, Matcha J. A rare case of pancake kidney with glomerulonephritis. Saudi J Kidney Dis Transpl [serial online] 2019 [cited 2021 Jan 17];30:549-52. Available from: https://www.sjkdt.org/text.asp?2019/30/2/549/256867

   Introduction Top

Common developmental anomalies of the kidney are horseshoe kidney and renal ectopia.[1] Pancake, disc, shield, or doughnut kidney is that which has joined at the medial borders of each pole to produce a doughnut or ring-shaped mass. When there is more extensive fusion along the entire medial aspect of each kidney, a disc or shield shape is created. The isthmus is not seen since there is complete fusion, looking like overlapping of the kidneys. The pelvis is anteriorly placed, and the ureters remain uncrossed. Each collecting system drains its respective half of the kidney and does not communicate with the opposite side.[2]

The exact incidence of pancake kidney is not known. Few case reports have been described in the literature, most of them as an incidental finding with conservative management. There are around 18 cases reported in PubMed. We present a brief review of its clinical presentation, embryological development, and management.

   Case Report Top

A 27-year-old man with no comorbidities was admitted to the hospital with complaints of facial puffiness and leg swelling of one- month duration. He had one episode of painless hematuria three days before admission. There was no history of joint pains, skin rash, oral ulcers, fever, or lower urinary tract symptoms.

On examination, the patient was alert and oriented. The temperature was normal, blood pressure: 110/80 mm Hg, pulse: 82 beats/min, respiratory rate: 22 breaths/min. The patient had bilateral pitting pedal edema. The abdominai examination revealed a mass of size 10 cm × 9 cm, palpable beneath the anterior abdominai wall in the periumbilical region with no tenderness. Other systemic examination was normal.

On investigation, urine routine showed 2+ albumin, 6–8 pus cells, 2–3 red blood cells per high-power field, and urine protein-creatinine ratio: 6.50. Blood urea nitrogen was 49 mg/dL, creatinine was 3.7 mg/dL, total white cell count was 15,300 cells/mm3, hemoglobin was 12.5 g/dL and platelet count was 2.5 × 105 platelets/μL, serum albumin was 2.0 g/dL, C3 was 100 mg/dL, C4 was 60 mg/dL, anti-streptolysin O titer was 200, anti-nuclear antibodies were negative, and blood and urine culture showed no growth.

Ultrasound of the abdomen showed pancake kidney in the umbilical quadrant with right side measuring 12.0 cm × 5.0 cm and left side measuring 11.5 cm × 4.5 cm with mild increased echoes and normal corticomedullary differentiation [Figure 1].
Figure 1: Ultrasound of the abdomen shows kidney seen anterior to the spine. Both poles of the kidney are seen on either side of the spine.

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Computed tomography of kidneys, ureters, and bladder showed both kidneys in the umbilical region, in the midline. The upper and lower poles of the kidneys appeared to be fused. The ureters were seen to arise from the anterolateral aspect of the kidney, features suggestive of pancake kidney [Figure 2].
Figure 2: Computed tomography - coronal section shows pancake kidney in the umbilical region (arrow).

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Since the patient had nephrotic proteinuria, renal biopsy was performed under ultrasound guidance with the patient in supine position.

Light microscopy showed mesangial hyper-cellularity and matrix expansion in all the glomeruli. One glomerulus showed increased neutrophilic infiltration. Tubules showed red blood cell and hyaline casts. Tubular atrophy and interstitial fibrosis was 5%. About 20% of blood vessels showed intimal hyalinosis and luminal narrowing. Immunofluorescence showed mesangial deposits of IgA 3+ [Figure 3]. Electron microscopy was not performed for this patient due to logistic reasons. Hence, the diagnosis of chronic IgA nephropathy with pancake kidney was made.
Figure 3: (a) Light microscopy shows mesangial hypercellularity and matrix expansion. (b) Immunofluorescence shows 3+ IgA mesangial deposits.

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The patient was treated conservatively with oral steroids in view of nephrotic proteinuria. The patient was discharged with serum creatinine of 1.9 mg/dL with urine output of 2 L/day.

The patient was on regular follow-up. After three months, investigations showed serum creatinine of 0.8 mg/dL and urine protein creatinine ratio was 0.5. Steroids were tapered and stopped.

Informed consent was obtained from the patient before reporting the case.

   Discussion Top

Numerous embryologic theories have sought to provide an explanation for anomalies of position and fusion of kidneys, which occur very early in gestation. Faulty ureteral bud development, abnormalities of renal vasculature limiting ascent, and teratogenic factors have been offered as explanations. In literature, it is also found that abnormally located umbilical artery may force the metanephric masses into opposition and cause fusion and after the fusion occurs cranial ascent to the lumbar position is impaired by the retroperitoneal structures.[3]

Wilmer in 1938 was the first to describe the logical categorization of fusion anomalies of the kidney, while McDonald and McClellan in 1957 redefined and expanded the classification given by Wilmer.[2] There are two types of renal ectopia: simple renal ectopia and crossed renal ectopia (i.e., crossed ectopia with fusion, crossed ectopia without fusion, solitary crossed ectopia, and bilateral crossed ectopia).

Pancake kidney is a very rare type of fused renal ectopia, and its exact incidence is unknown. Looney and Dodd were the first to define and describe the pancake kidney.[4]

In the literature, there have been cases of fused pelvic kidney reported to have concomitant anomalies such as Fallot tetralogy, vaginal absence, sacral agenesis, and caudal regression.[5] Chromosomal syndromes have been shown to be associated with genitourinary anomalies, and a series of cases was seen with 9p trisomy, 9p tetrasomy, strabismus, pancake kidney, and undescended testis. However, our patient presented with only pancake kidneys without any other abnormalities. A rare type of pancake kidney with cysts and single ureter was reported from Brazil with no symptoms. However, our patient presented with hematuria and swelling of upper and lower limbs which led us toward the diagnosis of a case with rare anomalies.[6]

The arterial supply of the pancake kidney is almost always constant since it lies in the pelvis. The arteries may branch from the iliac arteries or the distal part of the aorta. The veins drain into the iliac veins or the inferior vena cava.[7]

Patients with pancake kidney are usually asymptomatic but may present with features of urinary tract infection, fever, and vague lower abdominal pain. The presence of pancake kidney may predispose the patient to recurrent urinary tract infections and the formation of stones due to the probable rotation anomaly of the collecting system and short ureters, which are prone to stasis and obstruction.

If there are features of renal failure or obstructive uropathy, surgery is warranted. Division of the parenchyma may lead to renal vascular damage, necrosis of the kidney, infarction of the kidney, or postoperative renal failure.[8] Asymptomatic cases can be managed conservatively.

This case is unique because there are no reported cases of pancake kidney in literature where renal biopsy was performed, and the patient was treated conservatively for underlying glomerular disease.

The long-term follow-up of renal function, which can help detect complications such as urinary tract infection, calculi, and obstruction are required in patients with pancake kidney.

   Declaration of Patient Consent Top

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given his consent for his images and other clinical information to be reported in the journal. The patient understands that name and initials will not be published, and due efforts will be made to conceal identity, but anonymity cannot be guaranteed.

Conflict of interest: None declared.

   References Top

Yosypiv IV. Congenital anomalies of the kidney and urinary tract: A genetic disorder? Int J Nephrol 2012;2012:909083.  Back to cited text no. 1
Wein AJ, editor. Campbell-Walsh Urology. 9th ed. China: Philadelphia: Saunders/Elsevier. 2007. p. 3283-9.  Back to cited text no. 2
Kaufman MH, Findlater GS. An unusual case of complete renal fusion giving rise to a ‘cake’ or ‘lump’ kidney. J Anat 2001;198:501-4.  Back to cited text no. 3
Looney WW, Dodd DL. An ectopic (pelvic) completely fused (cake) kidney associated with various anomalies of the abdominal viscera. Ann Surg 1926;84:522-4.  Back to cited text no. 4
Heidempergher M, Landriani N, Airaghi C, et al. Pancake polycystic kidney: Case report. Arch Ital Urol Androl 2012;84:276-8.  Back to cited text no. 5
Calado AA, Macedo A Jr., Srougi M. Cake kidney drained by single ureter. Int Braz J Urol 2004;30:321-2.  Back to cited text no. 6
Glenn JF. Fused pelvic kidney. J Urol 1958; 80:7-9.  Back to cited text no. 7
Tiwari AK, Choudhary AK, Khowal H, Chaudhary P, Arora MP. Pancake kidney: A rare developmental anomaly. Can Urol Assoc J 2014;8:E451-2.  Back to cited text no. 8

Correspondence Address:
Indhumathi Elayaperumal
Department of Nephrology, Sri Ramachandra Institute of Higher Education and Research, Chennai - 600 116, Tamil Nadu
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DOI: 10.4103/1319-2442.256867

PMID: 31031396

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