Renal cyst - Bosniak type IIF (CEUS)

Case contributed by Dr Balint Botz


Referred for evaluation of a complex renal cyst detected incidentally by routine US.

Patient Data

Age: 60 years
Gender: Male

Noncontrast US

B-mode US demonstrates a cortical complex cyst with thick, irregular septae, some of which show distal shadowing and twinkling artefacts suggesting calcifications. Neither color Doppler, nor superb microvascular imaging demonstrates obvious septal vascularity.



Here some speckled artefacts are seen, likely due to the internal calcifications. 

After contrast injection (SonoVue) the cyst shows no abnormal peripheral enhancement that could signal a presence of a soft tissue component, however the septae are to a small extent penetrated by the microbubbles. The observed enhancement characteristics put the lesion into the Bosniak IIF category.

Case Discussion

A complex cyst was found incidentally in an earlier ultrasound of the right kidney.

After confirming the complex nature of the cyst the role of CEUS will be to demonstrate any septal enhancement, or an otherwise occult peripheral soft tissue component, while we have to keep in mind that calcifications will likely cause artefacts during contrast enhanced imaging as well.

The actual CEUS - as always - is preceeded by a thorough re-evaluation of the lesion. Here the CEUS shows a typical CEUS appearance of a Bosniak IIF complex cyst. Cysts with septal enhancement - however minimal it may be - require regular follow-up. 

It is a good practice to document the lesion again after switching to the CEUS preset but before the injection of contrast (T:0), to register any intrinsic tissue artefacts present within.


- As of 2019 renal CEUS is considered an off-label use in most countries. 

- Due to the otherwise prohibitively large size of such imaging datasets the cine acquisitions had to be truncated, and downgraded (compression). 

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Case information

rID: 72117
Published: 9th Nov 2019
Last edited: 10th Nov 2019
System: Urogenital
Inclusion in quiz mode: Included
Institution: University of Pécs

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