Renal Mass腎臟問題

Large solid vascular renal masses are usually cancerous. Such patients may present with  haematuria but many masses are picked up earlier at health screenings. There is however, no role for routine screening for renal masses except in those with such a strong family history or previous history. An incidental mass of the right kidney at the  lower pole, 5 x 4 cm is such an example. The standard practice nowadays is to have another imaging modality to confirm the ultrasound findings, especially any tumour thrombus in the renal vein and IVC.  The CT can also help to look for any para-aortic lymphadenopathy The commonest benign renal masses viz AML angiomyolipoma and oncytoma may exhibit characteristic lesions on CT. I will also do a chest x-ray at the same time.


One option is to do percutaneous ultrasound guided Trucut biopsies of the lesion.  However, the limitation of this is that  the  biopsy may not be representative of the tumour as renal cell carcinoma is heterogenous.  Biopsy can also cause bleeding and associated with the theoretical risk of biopsy tract seedling. One would also require a good uro-histopathologist to make a diagnosis. I would usually recommend a biopsy if we are thinking of systemic therapy without a nephrectomy, e.g. in the presence of metastatic disease.


One option is to remove the entire kidney with the tumour, for completeness of the surgery.


However, I would think the standard management would be a partial nephrectomy.  Partial nephrectomy is more complicated than total nephrectomy. It requires control of the renal vein, renal artery and probably
the insertion of ureteric catheter so that methylene blue can be  injected to detect any breach of the pelvi-calcyeal system which needs to be sutured. As the surgical margin  is renal tissue, there is also an increased risk of secondary haemorrhage, in addition to urinary fistula.  As with most surgeries, it can be done by three approaches: open, laparoscopic or robotic.  The later two usually takes longer.


“Minimally” invasive therapy includes cryoablation and radiofrequency. These ablative energies may be applied percutanously under ultrasound guide or laparoscopically. Tumour destruction is still incomplete. However, I would recommend such “MIT” only to patients who are unfit for surgery or who has
multiple bilateral lesions  where surgery is difficult.


The approach in small (<4cm) renal masses (SRM) is more conservative, which may include active surveillance in masses <3cm (incidence of primary metastatic disease 2.4 % compared to 8.4% if mass is 3-4cm)

Dr Clarence Lei Chang  Moh, FRCS Urol
clarencelei@gmail.com
20 Jan 2012