Renal Mass - Causes, Symptoms, Diagnosis, and Treatment

Introduction

There are two bean-shaped organs on either side of the spine, known as kidneys. The main role of kidneys is to filter the blood and remove waste products from the body. An abnormal growth in one or both of the kidneys is known as a renal mass. This article will explore the causes, diagnosis, and treatment options for renal masses.

What Are the Causes of Renal Mass?

There are various causes of renal masses, which are defined as any abnormal growth or lump in the kidney. These can include benign and malignant tumors, cysts, and infections. The primary causes of renal masses are as under:

Malignant Tumors

• Renal Cell Carcinoma: This type of cancer is the most common cause of renal masses. Renal cell carcinomas are further classified into various subtypes clear cell renal cell carcinoma, chromophobe renal cell carcinoma, papillary renal cell carcinoma, and collecting duct carcinoma.

Benign Tumors:

• Angiomyolipoma: This type of tumor comprises fat, blood vessels, and muscle cells and is usually harmless.

• Oncocytoma: This type of tumor is typically benign and made up of cells called endocytosis.

• Renal Adenoma: This type of tumor is also typically benign and made up of glandular cells.

• Leiomyoma: This type of tumor comprises smooth muscle cells and is usually harmless.

Cysts:

• Simple Renal Cysts: These are fluid-filled sacs that form on the surface of the kidney and are typically harmless.

• Polycystic Kidney Disease: This inherited condition where cysts develop on the kidneys over time can lead to kidney failure.

• Medullary Cystic Disease: This is a rare genetic disorder where cysts develop in the medulla or inner part of the kidney.

Infections:

• Pyelonephritis: The condition of urinary tract infection can cause inflammation in the kidney.

• Renal Abscess: This rare condition where pus collects in the kidney.

• Xanthogranulomatous Pyelonephritis: This is a rare and severe form of kidney infection where the kidney tissue becomes swollen and infected.

Other:

• Trauma: Injuries to the kidney can cause renal masses to form.

• Renal Infarction: This occurs when the blood supply to the kidney is blocked, leading to tissue damage.

• Lymphoma: This type of cancer affects the lymphatic system but can also affect the kidneys.

• Metastases From Other Cancers: Malignant cells originating from other regions of the body can metastasize to the kidneys, leading to the formation of renal masses.

What Are the Symptoms Associated With Renal Mass?

A renal mass is an atypical growth or lump in the kidney that may be benign or malignant. Symptoms can vary depending on the mass's size, location, and type. The symptoms associated with renal mass are as under:

• Abdominal Pain: Renal mass patients may experience persistent abdominal pain, which is sometimes mild or severe and often worsens over time. This pain is typically located in the back or side.

• Blood in Urine: It is a frequent symptom of renal mass, which can be detected visibly or through laboratory tests.

• Flank Mass: Some patients may have a palpable or visible lump in the flank region.

• Weight Loss: Unintended weight loss can indicate advanced renal mass or cancer. Patients with renal mass may experience weight loss without changing their lifestyle.

• Fatigue: Fatigue, weakness, and a general sense of feeling unwell are common symptoms associated with renal mass. The mass or cancer may cause these symptoms.

• High Blood Pressure: Renal mass can lead to high blood pressure, which may be challenging to manage with medications. Sometimes there is no history of hypertension, but the patients may still experience high blood pressure.

• Fever: A fever may occur as a result of an infection or inflammation associated with the renal mass. This symptom is more common in cases where the mass is causing an infection.

• Anemia: Anemia or low hemoglobin levels may occur in advanced stages of renal mass or cancer, resulting in weakness, fatigue, and shortness of breath.

How to Diagnose Renal Mass?

Diagnosing a renal mass usually requires a combination of different diagnostic methods, including imaging tests, clinical evaluation, and biopsy.

Imaging Tests for Renal Mass Diagnosis: Imaging tests are usually the first step in diagnosing a renal mass. The most common imaging tests used for renal mass diagnosis include:

• Ultrasound: High-frequency sound waves are used for generating images of the kidneys and the adjacent structures in a non-invasive manner.

• CT (Computed Tomography) Scan: A diagnostic imaging test that employs X-rays and computer technology to create comprehensive cross-sectional images of the kidneys and the nearby structures with precise detail.

• MRI (Magnetic Resource Imaging): Magnetic field and radio waves are used to generate images of the kidneys and surrounding structures.

• Clinical evaluation for renal mass diagnosis

Reviewing Medical History and Symptoms:

• Ask questions about any medications taken.

• Palpating the abdomen to feel for any masses.

• Biopsy for renal mass diagnosis.

Blood Tests for Renal Mass Diagnosis:

Blood tests may also be used to evaluate kidney function and assess for any abnormalities. Some common blood tests used for renal mass diagnosis include:

• Complete blood count (CBC).

• Basic metabolic panel (BMP).

• Liver function test (LFT).

What Is the Treatment of Renal Mass?

Here are some common treatment options for renal mass:

• Active Surveillance: Active surveillance or watchful waiting may be recommended for small renal masses that are less than 1.5748 inches in size and are slow-growing. Regular imaging and blood tests are conducted to monitor the mass and detect any changes in size or behavior.

• Surgery: Surgical intervention is the prevailing choice for addressing renal masses, commonly chosen as the primary treatment option. Two common types of surgery for renal mass include:

  • Partial Nephrectomy: This minimally invasive surgery removes only the part of the kidney containing the mass while preserving the healthy tissue.

  • Radical Nephrectomy: This extensive surgery removes the entire kidney, along with the mass and surrounding tissue.

• Ablation Therapy: Ablation therapy destroys the renal mass using heat or cold. This therapy is usually advised for patients who cannot undergo surgery or for small masses that are not suitable for surgery. Two common types of ablation therapy include:

• Radiofrequency Ablation (RFA): High-energy radio waves heat and destroy the mass in this procedure.

• Cryoablation: This procedure freezes and destroys the mass using extreme cold.

• Radiation Therapy: In some cases, it is used to treat renal mass, particularly when cancer has spread to other parts of the body.

• Chemotherapy: Chemotherapy is not a common treatment for renal mass. It may also be used in those cases where cancer has already spread to other body parts.

Conclusion:

Renal masses are frequently seen in clinical practice and require a comprehensive understanding of clinical, radiological, and pathological features. Management of renal masses has become more personalized with advancements in imaging and molecular characterization. The preferred treatment for localized tumors is surgical removal, but active surveillance and ablative techniques are effective for certain patients. Targeted therapies and immunotherapies have revolutionized the management of metastatic renal cell carcinoma. A multidisciplinary approach involving specialists such as urologists, radiologists, medical oncologists, and pathologists is necessary for optimal patient outcomes.