Image shows:Axial CECT of abdomen shows a heterogeneous enhancing mass (arrows) in the left kidney which represents an RCC.
Renal cell carcinoma (RCC) is the commonest primary malignant renal tumour in adult. Most of them are clear cell type. Other less common types are papillary, chromophobe and sacromatoid,
which account for the remaining 20%.
On plain radiographs, the renal shadow may be enlarged, but it could be normal if the tumour is small. The tumour may be hypo/isoechoic on ultrasound scan
Contrast enhanced CT features of renal cell carcinoma (RCC) include :
– Heterogeneous renal mass – hypodense components suggest areas of necrosis or cyst formation
– Inhomogeneous contrast enhancement- indicate hypervascular nature of tumour
– Soft tissue within right renal vein and IVC – due to venous tumour
invasion which is more common in RCC than other malignant renal tumours .
– Intralesional calcification (15-20%)
– Streaky perinephric fat suggestive of tumour extension to perinephric space
– Thickening of Gerota’s fascia due to tumour invasion or sympathetic inflammation
– Enlarged lymph nodes in renal hilum.
Approximately 1-3% of RCC are bilateral, especially in Von Hippel Lindau syndrome (uncommon autosomal dominant disease with multiple tumours involving CNS, kidney, adrenal, pancreas and liver).
Transitional cell carcinoma (TCC) is a less common primary malignant tumour occurring in the kidney. Features which help to differentiate TCC from RCC include:
– More central location (because of urothelial in origin)
– Less likely to have calcifi cation (1-5%)
– Vascular invasion is rare
– No cystic component