Renal cell carcinoma overview

# Overview

# Historical Perspective
Renal cell carcinoma was first described in 1826. Following contradictory hypotheses regarding the origin of renal tumors, it was not until 1960 that Oberling and colleagues showed that renal carcinomas originate from renal cells.

# Classification
Classification of renal cell carcinomas according to histopathological subtypes is based on the 1997 classification by Heidelberg and colleagues. Classification may also be according to the stage of renal cell carcinoma, which often is based on Robson classification system or the tumor-lymph node-metastasis (TNM) system.

# Pathophysiology
The pathophysiology of renal cell carcinomas plays an important role in differentiating different types of renal cell carcinomas and in choosing appropriate targeted medical therapies. Sporadic forms of clear cell renal carcinomas, the most common form of renal cell carcinomas, have similar pathophysiological mechanisms to those of von Hippel Lindau (VHL) disease. On the other hand, MET proto-oncogene seems to play a role in the disease pathogenesis of papillary forms of renal cell carcinoma. Uniquely also, oncocytomas are benign tumors that arise from type A intercalated cells, whereas chromophobe renal cell carcinoma arises from type B intercalated cells.

# Causes
The causes of renal cell carcinoma include von hippel-lindau (VHL), hereditary paragangliomas, leiomyomatosis, birt-hogg-dube syndrome, and several other genetic factors.

# Differentiating Renal cell carcinoma from other Diseases
The differential diagnosis of renal cell carcinomas includes metastastic disease, cysts, abscesses, lymphomas, and other benign and malignant tumors, and associated syndromes.

# Epidemiology and Demographics
In 2011, the age-adjusted prevalence of kidney cancer was 85.9 per 100,000 in the United States, the incidence was 15.28 per 100,000 persons. The male to female ratio is approximately 2 to 1. The median age of presentation is typically 60 years old.

# Risk Factors
Common risk factors of renal cell carcinoma include cigarette smoking, obesity, hypertension, end-stage renal failure, acquired cystic renal disease, acetaminophen and analgesic drug use, asbestos or trichloroethylene exposure, tuberous sclerosis, von-Hippel Lindau, hereditary paraganglioma, leiomyomatosis, and birt-hogg-dube syndrome.

# Screening
There are currently no guidelines for screening for renal cell carcinoma.

# Natural History, Complications and Prognosis
Common complications of renal cell carcinoma include hypertension, hypercalcemia, budd-chiari syndrome, hepatic vein thrombosis, polycythemia, renal failure, metastasis. Prognosis is generally poor, and the 5-year mortality of renal cell carcinoma is approximately 73.2%.

# Diagnosis

## Diagnostic study of choice
A needle biopsy should always be performed when the finding of a renal mass is detected on imaging.

## History and Symptoms
Common symptoms of renal cell carcinoma include hematuria, flank pain, palpable abdominal mass,weight loss and anorexia.

## Physical Examination
Common physical examination findings of renal cell carcinoma include low body mass index, high blood pressure, palpation of abdominal mass, auscultation of abdominal bruit, varicocele, muscle atrophy, skin pallor, facial flushing, and supraclavicular lymphadenopathy.

## Laboratory Findings
Laboratory findings of renal cell carcinoma include anemia, polycythemia, hypercalcemia, elevated ESR, elevated liver function tests, elevated alkaline phosphatase, elevated lactate dehydrogenase, elevated serum creatinine, hematuria, and cancer cells on urine cytology.

## Electrocardiogram
There are no ECG findings associated with renal cell carcinoma.

## X-ray
There are no x-ray findings associated with renal cell carcinoma. However, an x-ray may be helpful in the diagnosis of pulmonary metastasis of renal cell carcinoma.

## Ultrasound
Ultrasound may be helpful in the diagnosis of renal cell carcinoma. Ultrasound may be helpful when CT scan results are equivocal.

## CT scan
Renal CT scan may be helpful in the diagnosis of renal cell carcinoma. CT may be used to detect neoplastic masses that may define renal cell carcinoma or metastasis of primary cancer.

## MRI
Renal MRI may be helpful in the diagnosis of renal cell carcinoma. Due to the use of IV gadolinium in MRI, the risk of nephrogenic systemic fibrosis (NSF) must always be considered.

## Other Imaging Findings
PET CT and angiography may be helpful in the diagnosis or following-up patients with renal cell carcinoma. Bone scan is recommended in patients with elevated alkaline phosphatase to rule out bone metastasis.

## Other Diagnostic Studies
There are no other diagnostic studies associated with renal cell carcinoma.

# Treatment

## Medical treatment
The medical therapies of renal cell carcinoma include chemotherapy, hormone treatment, immunotherapy, and targeted therapy.

## Surgery
Surgery is the mainstay of treatment for renal cell carcinoma. Partial nephrectomy and ablation are recommended for patients who develop small renal masses. For patients with locally advanced renal tumors, radical nephrectomy is recommended. Moreover, radical nephrectomy or organ sparing treatment, along with the use of interferon alfa, is also used as part of a more aggressive management plan in cases with metastatic renal tumors.

## Primary prevention
Primary prevention strategies include early screening, changing lifestyle, decreasing exposure to occupational risk factors, and controlling of hypertension.

## Secondary prevention
There are no established measures for the secondary prevention of renal cell carcinoma.