Answers to Case 1-4-1
1. Figure 2.11.1a,b,c are CT images through the upper abdomen. There is an exophytic
multilocular cystic lesion arising from the anterior aspect of the lower
pole of the right kidney. This demonstrates nodular wall thickening and multiple
enhancing nodular septations within it.
2. This is a Bosniak type 3 cyst. Other CT features that may be seen with a type 3
cyst are thick or irregular calcifi cation, irregular margin or nodularity or a nonenhancing
nodular cyst.
3. With a type 3 cyst the likelihood of malignancy is 50% (ranging from 30 to
60%), and surgery (partial or total nephrectomy) is indicated in many of these
patients. Patients who are not suitable for surgery due to co-morbidity may be
considered for minimally invasive treatment such as cryotherapy or radiofrequency
ablation. Where the history or clinical fi ndings strongly suggest an alternative
diagnosis (such as infection) interval follow-up or biopsy of the lesion
may be indicated.