From the Research
Bosniak 1 and 2 kidney cysts should be followed up with a single ultrasound or CT scan at 6-12 months, and if stable, no further imaging is necessary, as indicated by the most recent and highest quality study 1. The management of Bosniak 1 and 2 kidney cysts prioritizes minimizing unnecessary radiation exposure, patient anxiety, and healthcare costs while ensuring the detection of any potential malignancy.
- Bosniak 1 cysts are simple cysts with no concerning features, and their malignancy potential is essentially zero.
- Bosniak 2 cysts have some minimally complex features but remain very likely benign, with a malignancy potential of less than 5%. The 2019 Bosniak classification system, as compared to the 2005 version, offers improved diagnostic specificity and inter-rater reliability, particularly in CT imaging, as demonstrated by a systematic review and meta-analysis 1. Key points to consider in the follow-up of Bosniak 1 and 2 kidney cysts include:
- The use of ultrasound or CT scans for follow-up, with CT being more sensitive for detecting changes in cyst complexity.
- The importance of assessing cyst stability, with changes in appearance or size warranting further evaluation.
- The role of patient symptoms, such as pain, hematuria, or signs of infection, in prompting additional imaging or intervention. Overall, the approach to following up Bosniak 1 and 2 kidney cysts should balance the need for vigilance with the potential risks and costs associated with excessive surveillance, as supported by the most recent evidence 1.