Radiology Tutor
Bosniak classification of cystic renal lesions BETA
Scroll down for cystic lesions (tick the appropriate check box and only fill in the appropriate section, either hyperdense or cystic, separated by the horizontal lines - use the reset button to start again/assess a different lesion). You really don't have to fill in all sections, just leave the defaults if they don't apply - don't worry, it wont downgrade the lesion!
†Enhancement is >20 HU increase. Intermediate enhancement is an increase of 10-20 HU and no enhancement is <10 HU.
Bosniak first described his approach in 1986. There have been numerous follow up papers, some of which are present in the references section below.
Suitable follow up could be at 6 months then yearly for 4 years.2,3
There may be minimal enhancement of septa and walls in category II and IIF cysts4, but there should be no other enhancement and if there is clear enhancement then it is likely to be a category III lesion.
References
- Bosniak, M. A. The current radiological approach to renal cysts. Radiology 158, 1–10 (1986).
- Bosniak, M. A. Diagnosis and management of patients with complicated cystic lesions of the kidney. Am. J. Roentgenol. 169, 819–821 (1997).
- Hindman, N. M., Hecht, E. M. & Bosniak, M. A. Follow-up for Bosniak Category 2F Cystic Renal Lesions. Radiology 272, 757–766 (2014).
- Israel, G. M. & Bosniak, M. A. Calcification in Cystic Renal Masses: Is It Important in Diagnosis? Radiology 226, 47–52 (2003).
- Silverman, S. G., Israel, G. M., Herts, B. R. & Richie, J. P. Management of the Incidental Renal Mass. Radiology 249, 16–31 (2008).
- Israel, G. M. & Bosniak, M. A. Follow-up CT of moderately complex cystic lesions of the kidney (Bosniak category IIF). AJR Am. J. Roentgenol. 181, 627–633 (2003).
- Smith, A. D. et al. Bosniak Category IIF and III Cystic Renal Lesions: Outcomes and Associations. Radiology 262, 152–160 (2012).