March 25, 2026
Renal cell carcinoma (RCC) is the most common renal cancer. Symptoms can include hematuria, flank pain, a palpable mass, and fever of unknown origin (FUO). However, symptoms are often absent, so the diagnosis is usually suspected based on incidental findings. Diagnosis is confirmed by CT or MRI and occasionally by biopsy. Treatment is with surgery for early disease and systemic therapy, an experimental protocol, or palliative therapy for advanced disease.
RCC, an adenocarcinoma, accounts for 90 to 95% of primary malignant renal tumors. Less common primary renal tumors include transitional cell carcinoma, Wilms tumor (most often in children), and sarcoma.
In the United States, about 81,610 new cases of RCC and other kidney tumors and 14,390 deaths (2024 estimates) occur each year (1). RCC occurs more often in men (male:female incidence is about 2:1). People with RCC are usually diagnosed between 65 and 74 years old. Risk factors include the following:
RCC can trigger thrombus formation in the renal vein, which occasionally propagates into the vena cava. Tumor invasion of the vein wall is uncommon. RCC metastasizes most often to the lymph nodes, lungs, adrenal glands, liver, brain, and bone.
Symptoms usually do not appear until late, when the tumor may already be large and metastatic. Gross or microscopic hematuria is the most common manifestation, followed by flank pain, fever of unknown origin (FUO), and a palpable mass. Other nonspecific symptoms can include fatigue, weight loss, and early satiety. Sometimes hypertension results from segmental ischemia or pedicle compression. Paraneoplastic syndromes occur in 20% of patients. Polycythemia can result from increased erythropoietin activity. However, anemia may also occur. Hypercalcemia is common and may require treatment. Thrombocytosis, cachexia, or secondary amyloidosis may develop.
Renal Cell Carcinoma (Contrast CT Scan)
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Most often, a renal mass is detected incidentally during abdominal or spinal imaging (eg, CT, ultrasonography, MRI) done for other reasons. Otherwise, diagnosis is suggested by clinical findings and confirmed by abdominal CT before and after injection of a radiocontrast agent or by MRI. (See Genitourinary Imaging Tests.) A renal mass that is enhanced by radiocontrast strongly suggests renal cell carcinoma (RCC). CT and MRI also provide information about local extension and nodal and venous involvement. MRI provides further information about extension into the renal vein and vena cava and has replaced inferior vena cavography. Ultrasonography and intravenous urography may show a mass but provide less information about the characteristics of the mass and extent of disease than do CT or MRI.
Often, nonmalignant and malignant masses can be distinguished radiographically, but sometimes biopsy or surgery is needed for confirmation. Needle biopsy does not have sufficient sensitivity when findings are equivocal; it is recommended only when the diagnosis would impact treatment choice, such as when there is an infiltrative pattern instead of a discrete mass, when the renal mass may be a metastasis from another known cancer, or sometimes to confirm a diagnosis before chemotherapy or systemic therapy for metastatic renal masses.
Three-dimensional CT, CT angiography, or magnetic resonance angiography is used before surgery, particularly before nephron-sparing surgery, to define the nature of RCC, to more accurately determine the number of renal arteries present, and to delineate the vascular pattern. (See Genitourinary Imaging Tests.) These imaging techniques have replaced aortography and selective renal artery angiography.
A chest x-ray and liver tests are essential. If chest x-ray is abnormal, chest CT is done. If alkaline phosphatase is elevated, bone scanning is needed. Serum electrolytes, blood urea nitrogen (BUN), creatinine, and calcium are measured. BUN and creatinine are unaffected unless both kidneys are diseased.
Fluorodeoxyglucose (FDG) PET/CT is not routinely done in most patients with primary RCCs, but it may be beneficial for preoperative staging in high-risk tumors and to assess the response to systemic therapies in metastatic disease. A new PET imaging agent, zirconium-89 (89Zr)-deferoxamine (DFO)-girentuximab, may identify clear cell renal cell carcinoma (ccRCC) with high sensitivity and specificity (1).
Source: MSD Manuals. “Renal Cell Carcinoma.”
By Thenappan Chandrasekar, MD, University of California, Davis
Reviewed By Leonard G. Gomella, MD, Sidney Kimmel Medical College at Thomas Jefferson University
Available at: https://www.msdmanuals.com/professional/oncology/genitourinary-cancers/renal-cell-carcinoma
Copyright Notice: © 2026 Merck & Co., Inc., Rahway, NJ, USA and its affiliates. All rights reserved.
This content is an excerpt and has not been modified.
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