CASE 10511 Published on 03.12.2012

Supranumerary kidney and duplication of the gallbladder

Section

Uroradiology & genital male imaging

Case Type

Clinical Cases

Authors

Cekaj E, Osmënaj R

1- Regional Hospital of Durres, Albania
2- University hospital Center "Mother Tereza" of Tirana, Albania

Patient

32 years, female

Categories

Area of Interest Urinary Tract / Bladder, Biliary Tract / Gallbladder ; Imaging Technique CT

Procedure Diagnostic procedure ; Special Focus Congenital ;

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Clinical History

The patient presented to the emergency department with sudden severe back pain and vomiting. No abdominal defense or changes in blood chemistry values were present. An acute abdomen pathology was suspected in emergency department and the patient was referred for an abdomen computed tomography (CT) examination.

Imaging Findings

In CT (without contrast media, CM) a left para-aortic solid mass with a small calcification within it was observed (Fig 1a). After intravenous CM was administered, in arterial phase the mass presented as a free supranumerary kidney measuring 28.3mm x 33 mm (Fig 2a, 3a) and its parenchyma, its chalices (Fig 2b) and even its feeding artery (Fig 2c, 3b) were well identifiable. In late phase scanning (Fig 1c) its chalices were filled by excreted contrast but its ureter was not visualized. Upon checking the upper abdomen a double gallbladder was identified (Fig 4a, 4b).

Discussion

The free supernumerary kidney is probably the rarest anomaly encountered in the urinary tract. The embryological basis of the free supernumerary kidney is splitting of the metanephric blastema or the development of two separate metanephric blastemas, into which the partial or completely reduplicated ureteric stalks enter to form the two separate kidneys [1,2]. The supernumerary kidney is smaller, can be hypoplastic, mostly caudally to the normal left kidney and it is usually not well organized histologically [3].
Kidney stone is the most common pathological condition of the kidneys. The sensitivity and specificity of computed tomography (CT) for the diagnosis of a stone are above 95%, superior to those of intravenous urography, which was the previous gold standard. Consequently, CT is becoming the new gold standard in the diagnosis of colic pain in the evaluation of other tests, which may be biological, such as haematuria testing, or radiological, such as plain film, or a combination of abdominal plain film and ultrasonography. CT shows direct and indirect findings of colic pain due to a stone. The direct finding is the visualization of the calculus itself. Regardless of composition, almost all renal and ureteral stones are detected by CT because the attenuation of stones is higher than that of surrounding tissue, even if attenuation of uric acid stones is lower than the attenuation of calcium. Multidetector computed tomography (MDCT) with contrast media administration is the best choice to determine supranumerary kidney and in the meantime its stones [4, 5, 6].
Duplication of the gallbladder is a rare congenital anomaly, its prevalence is 1 per 4000 births [7]. It is thought to be due to exuberant budding of the developing biliary tree when the caudal bud of the hepatic diverticulum divides [8, 9]. Gallbladder duplication is classified after Boyden in divisa and duplex (duplex is subdivided in Y shape and H shape vesica fellea). Ultrasound is the first choice to examine the gallbladder with very high sensitivity and specificity. Multidetector computed tomography (MDCT) which offers multiplanar reformation of the images, especially associated with oral or intravenous biliary contrast media and MR cholangiography are non-invasive imaging modalities that can be more useful to evaluate the congenital abnormalities of gallbladder and the biliary tree. Invasive methods such are ERCP (endoscopic retrograde cholangiopancreatography) and transhepatic cholangiography can determine the diagnosis but they are usually prefered as last choice to do that [10].

Differential Diagnosis List

Stone in supranumerary kidney and duplicated gallbladder

Retroperitoneal mass

Para-aortic adenopathy

Choledochal cyst

Phrygian cap

Gallbladder diverticula

Heptic cyst

Final Diagnosis

Stone in supranumerary kidney and duplicated gallbladder

References

[1] Porter KA (1992) Development and congenital malformations of the kidneys. In: Symmers W St C, ed. The kidneys and the urinary tract. 3rd ed, Vol. 8. Edinburgh: Churchill Livingstone 47-72

[2] Campbell, M. F (1970) Urology, 3rd ed. London: W. B. Saunders page 1422

[3] Flyer MA (1994) Ectopic supernumerary kidney, another cause of a pelvic mass. Abdom Imaging 19:374–5 (PMID: 8075569)

[4] Luchs JS, Katz DS, Lane MJ et al (2002) Utility of hematuria testing in patients with suspected renal colic: correlation with unenhanced helical CT results. Urology 59:839–842 (PMID: 12031364)

[5] Poletti PA, Platon A, Rutschmann OT et al (2006) Abdominal plain film in patients admitted with clinical suspicion of renal colic: should it be replaced by low-dose computed tomography?. Urology 67:64–68 (PMID: 16413334)

[6] Catalano O, Nunziata A, Altei F et al (2002) Prima, helical CT versus selective helical CT after unenhanced radiography and sonography. AJR Am J Roentgenol 178:379–387 (PMID: 11804898)

[7] Tamm EP, Silverman PM, Shuman WP (2003) Evaluation of the patient with flank pain and possible ureteral calculus. Radiology 228:319–329 (PMID: 12819343)

[8] Ege G, Akman H, Kuzucu K, Yildiz S (2003) Acute ureterolithiasis: incidence of secondary signs on unenhanced helical CT and influence on patient management. Clin Radiol 58:990–994 (PMID: 14654033)

[9] E. A. Boyden (1926) The accessory gallbladder: an embryological and comparative study of aberrant biliary vesicles occuring in man and the domestic mammals. American Journal of Anatomy vol. 38, pp. 177–231

[10] M. Lamah, N. D. Karanjia, and G. H. Dickson (2001) Anatomical variations of the extrahepatic biliary tree: review of the world literature. Clinical Anatomy vol. 14, no. 3, pp. 167–172 (PMID: 11301462)

[11] P. R. Kothari, T. Kumar, A. Jiwane, S. Paul, R. Kutumbale, and B. Kulkarni (2005) Unusual features of gall bladder duplication cyst with review of the literature. Pediatric Surgery International vol. 21, no. 7, pp. 552–554 (PMID: 15889262)

[12] Ozgen, D. Akata, A. Arat, F. B. Demirkazik, M. N. Ozmen, and O. Akhan (1999) Gallbladder duplication: imaging findings and differential considerations. Abdominal Imaging vol. 24, no. 3, pp. 285–288 (PMID: 10227894)

Case information

URL:	https://www.eurorad.org/case/10511
DOI:	10.1594/EURORAD/CASE.10511
ISSN:	1563-4086

Figure 1

Axial CT view without CM

Note the left paraortic solid mass with a small calcification within it

Arterial phase axial image which shows the kidney structure. Note the contrast media around the calcification (renal stone)

Late phase axial image which shows the chalice full of excreted contrast media

Figure 2

Axial CT views with CM

Note that the supranumerary kidney measurements are 28.3 mm and 33 mm

Supranumerary kidney parenchyma and chalices are well identifiable, similar to those of normal kidneys

In this axial image the supranumerary kidney-feeding artery is well presented

Figure 3

3D volume rendering images

Note that the supranumerary kidney is positioned medially to left kidney, on the left of aorta

Feeding artery of the supranumerary kidney

Figure 4

Double gallbladder, axial arterial phase views

Note that the both gallbladders are easily identifiable with multiplanar reformation of MDCT. But it was impossible for us to do the proper classification after Boyden.