Kidneys
5.2cms Cyst in the Right Kidneylesion
2. Findings and Diagnosis
Septated Renal Cyst on CT 5.2cms
CT through the mid abdomen in axial projection shows a lobular cyst with fine septations in the mid portion of the right kidney.
Ashley Davidoff MD TheCommonVein.net 130769
CT through the mid abdomen in axial projection shows a lobular cyst with fine septations in the mid portion of the right kidney.
Ashley Davidoff MD TheCommonVein.net 130769
| Bosniak Category | Imaging Features | Malignancy Risk | Management |
|---|---|---|---|
| I | – Simple cyst – Thin wall, no septa, calcifications, or solid components – Water attenuation (<20 HU) – No enhancement |
~0% | Benign → No follow-up needed |
| II | – Minimally complex – Few thin septa – Fine or thin calcifications – No measurable enhancement – May include hyperdense cysts <5 cm (if well-marginated and non-enhancing) |
~0% | Benign → No follow-up needed |
| IIF | – Multiple thin septa – Possible minimal smooth thickening – May have minimal enhancement – May contain calcification, or be hyperdense >3 cm – No solid enhancing component |
~5% | Probably benign → Follow-up imaging recommended |
| III | – Thickened or irregular walls or septa – Measurable enhancement present – No obvious solid component |
~50% | Indeterminate → Surgical excision or biopsy may be warranted |
| IV | – Features of Category III plus: – Enhancing soft tissue component (nodule) – Irregular or thick enhancement |
~85–100% | High risk → Surgical excision recommended |
🧠 Key Terms Explained
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Enhancement = measurable increase in HU (>10–15 HU) after contrast → indicates vascularity (suspicious)
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Hyperdense cyst = high attenuation (40–90 HU) on non-contrast CT
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Septations = thin internal walls; suspicious if thickened or enhancing
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Solid components = most concerning for malignancy, especially if enhancing