Renal tumors biopsy

Multilocular cystic nephroma and cystic partially differentiated nephroblastoma cannot be distinguished on imaging, and biopsy is not recommended because it is usually not informative. The only difference between these two entities is the presence of embryonal cells within the septa in CPDN. Therefore, it is recommended that purely cystic renal tumors should be first surgically removed (SIOP 2001), the final diagnosis being obtained after pathological analysis. 

Vujanic GM, Kelsey A, Mitchell C et al (2003) The role of biopsy in the diagnosis of renal tumors of childhood Results of the UKCCSG Wilms tumor study 3. Med Pediatr Oncol 40(l) 18-22... 

After dilatation an Amplatz sheath is inserted over the last dilator. The dilators are then removed leaving only the Amplatz sheath and a guidewire in position. Once the tumor is visualized biopsies are taken both of the tumor and of the apparently normal renal pelvis. The tumor is then resected with diathermy. Tamponade of the tract is maintained with a 30-F nephrostomy catheter. The following day brachytherapy is given to the track to ensure that track tumor implantation does not occur (WooDHOUSE et al. 1986). It is stressed that this treatment is used only for low grade TCC or as... 

Kidney. Biopsies of the kidney are rarely performed because they are often interpreted as hemorrhagic or inconclusive, and most solid renal masses are surgically removed. Exceptional indications for biopsy are suggested lymphoma and metastasis to the kidney from another primary tumor, since these conditions are usually not treated surgically. The usual access route under GT guidance is posterior or lateral while the renal hilum should be avoided. 

Most renal masses can be characterized with high accuracy by noninvasive imaging alone, and a sohd non-fat-containing or complex renal mass should be considered a renal cell carcinoma until proven otherwise. Metas-tases to the kidney are usually small and multifocal or perinephric. Lymphomatous involvement of the kidneys also usually occurs in the setting of disseminated disease and is characterized by typical CT patterns like multiple small masses, spread from retroperitoneal disease, diffuse infiltration, and perinephric encasement. In a study by Lechevallier et al. (2000), CT-guided renal biopsy of 63 patients had an overall accuracy of 89%. Biopsy material was not sufficient for analysis in 15 patients (21%). Unsuccessful biopsy was related to lesion size biopsy was unsuccessful in 11 of 30 tumors (37%) of 3 cm or less, versus 4 of 43 (9%) of tumors greater than 3 cm. 

A 74-year-old man with multiple metastases and an unknown primary developed acute renal failure. He was given terlipressin 0.5 mg/hour via an infusion pump together with albumin and antibiotics and 4 days later developed an isolated large erythematous plaque on the scalp. Biopsy showed thrombosis of dermal capillaries. He died a few days later from tumor progression. 

Partial nephrectomy is sometimes considered in unilateral WT when the child has contralateral non-functioning kidney or associated renal disease or associated predisposing syndrome (SIOP 2001). Nevertheless, partial nephrectomy is contraindicated in unilateral multifocal tumors, central location, involvement of more than 1/3 of kidney, preoperative tumor rupture or biopsy, infiltration of extra-renal structures, intra-abdominal metastases or lymph nodes, thrombosis of RV or I VC, involvement of calyces or hematuria (SIOP 2001). 

Fig. 24.14. Juvenile renal cell carcinoma in a 9-year-old girl presenting with abdominal pain. Enhanced CT scan shows a non-specific heterogeneous tumor of the left kidney. Relative small tumor size and patient age are suggestive criteria for renal cell carcinoma and must lead to a diagnostic biopsy...

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