Renal Pathology

What Is Renal Pathology?

Renal pathology is a medical sub-specialty focusing on medical (non-tumor) diseases of the kidney.

A renal pathologist is a type of doctor with highly specialized training who analyzes tissues and focuses on diagnosing lesions of the renal system. They work with other specialists like nephrologists and transplant surgeons.

They examine tissues obtained from renal or open biopsies or nephrectomy using techniques like histopathology, immunohistochemistry, and molecular pathology to diagnose various conditions.

What Do Renal Pathologists Do?

Renal pathologists use different types of microscopes and other specialized tools and tests to examine tissue samples, to diagnose diseases affecting the glomerulus of the kidney (the filter), renal tubules and interstitium, renal vessels, or a combination of any of these.

What’s The Difference Between a Nephrologist and a Renal Pathologist?

For testing, diagnosis, and treatment of renal issues, you might begin by seeing a nephrologist. They can assess, diagnose, and treat many conditions. A nephrologist can also perform a biopsy when a diagnosis can’t be made, or further information is needed.

Tissue samples from the biopsy can be sent to a renal pathologist for further study. A pathologist typically works in a laboratory rather than directly with patients. They will work closely with your nephrologist or primary care physician to diagnose your condition and recommend the best treatment.

What Types of Tissues Do Renal Pathologists Study?

Renal pathology is a study of changes in the kidneys due to disease. Renal pathologists study tissue samples to look for signs of:

Cancer
Diabetic-related injury
Hypertension-related injury
Infection
Inflammation
Scarring

A renal pathologist is an expert in conditions like:

Acute kidney injury
Chronic kidney disease
Drug toxicity
Diabetic nephropathy
Focal segmental glomerulosclerosis
Glomerulonephritis
Glomerulopathy
HIV-associated kidney diseases
Lupus nephritis
Nephrosis

Techniques to Identify Renal Conditions

After a tissue sample is obtained and processed, a pathologist uses specialized techniques, tools, and processes to investigate its condition.

If the microscopic examination doesn’t provide clear answers, pathologists are experts in other testing techniques that may provide more information. Some methods and tools they use include:

Stains – Chemicals or stains can be applied to tissue samples to highlight signs of disease or cell abnormalities. Different stains are used to identify causes, foreign substances, and other markers that identify characteristics of the specimen.

Direct immunofluorescence – A special type of staining that helps identify autoimmune diseases.

Frozen section – A sample can be frozen and examined at once if a diagnosis is needed quickly.

Immunohistochemistry – This technique uses the body’s own antibodies to help identify the interaction between the antibodies and antigens triggering the immune system.

Flow cytometry – A technique of analyzing the identity and quantity of a type of cell or particle. Samples are suspended in fluid and passed through different light sources, lenses, and filters to generate wavelength data. Flow cytometry can measure characteristics like cell size, total DNA, and more.

Biomarker testing – Analyzing a sample for genes, proteins, or other biological substances that are present with cancer to provide information that can affect treatment.

What Do Results Look Like?

The results of a pathological examination are documented in a biopsy or pathology report, which includes information like:

A diagnosis
A description of the tissue sample
A microscopic description of the disease process discovered
Clinical data that helped support the diagnosis
Additional information to help determine treatment
If cancer is found, it may also include information to help form a treatment plan
Comments from the pathologist

The report is sent to the treating doctor, who will discuss the results with the patient.