Answers to Case 1-2-1
1. Greyscale (Fig.1-2-1.1a ) and colour Doppler (Fig. 1-2-1.1b ) ultrasound images
through the left kidney showing a hypoechoic region centrally within the interpolar
region. This has a mass like appearance and on colour Doppler ultrasound,
it has peripheral vascularity. There is no posterior acoustic enhancement in keeping
with a solid composition. Coronal (Fig.1-2-1.1c ) and axial (Fig. 1-2-1/1d )
postcontrast CT images through the upper abdomen which depict the region
noted on ultrasound. Although it also has a mass like appearance, the renal outline
is preserved although it does appear to bulge into the renal sinus fat. However,
and critically, it demonstrates isodense enhancement when compared to the
remainder of the renal parenchyma.
2. This is an example of junctional parenchyma, but more familiarly known as a
hypertrophic column of Bertin. The diagnostic features include location between
the overlapping portion of the upper and lower poles, and that it contains normal
renal tissue that is continuous with the adjacent renal cortex. Being functionally
normal, it shows normal echogenicity on US and normal enhancement and tracer
uptake on CT/MRI and nuclear medicine, respectively.
3. This is due to unresorbed renal parenchyma where the embryological upper and
lower pole moieties fuse. It is a normal variation and does not predispose to any
complication. It’s only clinical signifi cance is that it closely mimics a centrally
lying renal mass.
Lafortune M, Constantin A, Breton G, Vallee C. Sonography of the hypertrophied
column of Bertin. AJR Am J Roentgenol . 1986;146(1):53–56.
Yeh HC, Halton KP, Shapiro RS, Rabinowitz JG, Mitty HA. Junctional parenchyma:
revised defi nition of hypertrophic column of Bertin. Radiology . 1992;185(3):
725–732.