Renal cell carcinoma

Abstract

Renal cell carcinoma is the most common neoplastic lesion of the kidney, accounting for approximately 85% of all renal neoplasms; the vast majority of these tumors are adenocarcinoma. Nephroblastoma (Wilms tumor) accounts for 5 to 6%, transitional cell neoplasms of the renal pelvis account  for 7 to 8%, and the remainder are various sarcomas of renal origin. The diverse clinical signs and symptoms of renal cell cancer may challenge the most astute diagnostician. Previously known as “ the internist’s tumour,” perhaps in the 1990’s this tumour should be known as “ the radiologist’s tumour”. More and more patients are discovered incidentally at the time of radiographic procedures such as ultrasound or CT scan for nonurologic problems. Grawitz, in 1983, observed a resemblance of small yellow adenomas of the kidney to adrenal tissue and suggested the possibility of adrenal rests. Based on this observation, Birch-Hirschfeld introduced the term hypernephroid tumours or hypernephroma. Since then, the conceptually incorrect term “hypernephroma” has been utilized to describe renal tumours. With the advent of electron microscopy, conclusive demonstration that renal cell carcinoma arises from proximal convoluted tubule cells has emerged. Therefore, renal cell carcinoma is the preferred terminology for this tumour. C.T. Scan is more sensitive than US or IVU for detection of renal masses. A typical finding of RCC on CT is a mass that becomes enhanced with the use of intravenous contrast media. In general, RCC exhibits an overall decreased density in Hounsfield units compares with normal renal parenchyma but shows a heterogeneous pattern of enhancement or increased attenuation (slightly decreased from the surrounding parenchyma) when contrast is used. In addition to defining the primary lesion, CT scanning is also the method of choice in staging the patient by visualizing the renal hilum, perinephric space, renal vein and vena cava, adrenals, regional lymphatic, and adjacent, a CT scan of the chest is indicated. Patients who present with symptoms consistent with brain metastases should be evaluated with either head CT or MRI. Spiral CT with 3-dimensional reconstruction has become useful form evaluating tumors before enthrone-sparing surgery to delineate the 3-dimensionaal extent of the tumor and precisely outline the vasculature, which can aid the surgeon in preventing positive surgical margins (Holmes et al., 1977). Intra-operative ultrasonography is also often used to confirm the extent and number of masses in the kidney at the time of performing a partial nephrectomy.