If you have been seeing your doctor for mesothelioma symptoms, your doctor will order a biopsy to get a definitive diagnosis. A biopsy takes tissue samples from tumors and tests them for the presence of mesothelioma cells. Numerous types of biopsies exist, but the least invasive is a needle biopsy. Depending on your symptoms, imaging tests, and examination findings, your doctor may choose a needle biopsy over a surgical biopsy.
What is a Needle Biopsy?
Understanding what a needle biopsy is, how it works, and what you can expect during the process will help alleviate possible anxiety and allow you to better communicate with your doctor.
A needle biopsy is the only non-surgical biopsy method, making it the least invasive option. A needle biopsy requires no incision, so your doctor can perform it in-office, rather than the hospital, using only local anesthetic. Patients will not have to stay overnight in the hospital and will have relatively little down time.
As the name indicates, a needle biopsy utilizes a special needle to collect cells either from tissue or fluid in your body, depending on the type of needle biopsy and your specific symptoms. Your doctor will insert the needle into that symptomatic area (usually surrounding the lungs, stomach or heart) and will draw a fluid or tissue sample. The sample(s) will be sent to a pathologist to analyze for results.
Types of Needle Biopsies
There are a couple of different types of needle biopsies. Depending on the location of the symptoms and on whether the patient experiences fluid build-up as one of their symptoms. The possible options are:
Fluid Extraction for Cytology
Doctors may use a needle biopsy with either a large- or small-bore needle to draw fluid from the problem area of the patient’s body. Doctors also use this procedure to relieve patients of the discomfort from fluid build-up.
Your physician will send the sample to a specialist for cytology testing (when a fluid sample is placed on a slide and examined under the microscope). The specialist will look for the presence of cancer cells and will analyze and identify the type of cancer cell(s) present if any.
Based on disease location, doctors use one of three different needle biopsy procedures to withdraw fluid samples.
- Thoracentesis—When fluid is removed from the area between the chest wall and the lungs.
- Paracentesis—When fluid is removed from around the abdomen.
- Pericardiocentesis—When fluid is removed from the area between the heart and pericardium.
During the procedure, the doctor will drain all the fluid, not just a sample, to alleviate your symptoms.
The physician performing the biopsy may choose to use a CT camera or ultrasound to assist with proper placement of the needle. Regardless, this type of needle biopsy is a quick procedure that usually only requires local anesthetic and very little or no down time for the patient.
The downside of needle biopsies for fluid extraction is that they are not very reliable. Even if cancer is present in the body, there is no guarantee that the fluid sample sent to the specialist will contain cancer cells. As such, if the results from such a biopsy are negative, a doctor will likely follow-up by prescribing a surgical biopsy for more sure results.
Core Biopsy for Histology
During a core biopsy, doctors insert a special needle directly into the tumor to collect a tissue sample for analysis. A core biopsy uses a special needle with a tip meant for cutting and removing tissue. It is most common and recommended that the physician use a CT scan to guide the needle to ensure accuracy.
Like needle biopsies for removing fluid, a needle core biopsy is a quick procedure. It requires no incisions and only local anesthetic, allowing the patient to return to regular activity the same day. After the procedure, the tissue biopsy is sent to the a histopathologist to perform histology tests for analysis. Histopathologists use special stains specifically for identifying mesothelioma cancer cells.
A CT-guided core biopsy and histology test have a higher likelihood of accuracy than a fluid biopsy and cytology. However, the tumor must be in an easily accessible part of your body for a doctor to use this method. If the symptomatic area is the lungs and the suspected tumor is located in the chest, then a CT-guided needle biopsy becomes more possible.
Even if the doctor can collect a tissue sample from the tumor using a CT-guided biopsy method, the retrieved samples are sometimes too small to provide a definitive diagnosis. Doctors will usually collect multiple samples from multiple parts of the tumor for accurate diagnosis.
What do Needle Biopsies Detect?
Both fluid and tissue needle biopsies are used to detect cancer cells and provide an opportunity for diagnosis.
If a fluid sample was taken and sent to the specialist, then doctors perform a cytology test. Specialists use cytology tests to see the chemical makeup of the fluid and if there are cancer cells present.
If doctors do find cancer cells, they will perform additional tests to identify the specific type of cancer and determine whether it’s mesothelioma or another cancer, such as lung cancer. Additionally, a cytology test helps specialists determine the disease stage.
Since an absence of cancer cells in the fluid sample doesn’t mean the patient is cancer-free, there is a risk of inaccuracy with cytology testing. If the cytology test produces a negative result, then doctors often pursue a surgical biopsy to remove a solid tissue sample from the tumor or affected area.
If your doctor performs a CT-guided core needle biopsy—removing actual tissue from the tumor—the specialist will perform a histology test for analysis. The histology test involves separating the sample into small sections that can be examined under a slide. The specialist uses special stains to make cells more visible and distinguishable under the microscope.
From the histology results, specialists can see if cancer cells are present and can identify the exact cell type.
If doctors suspect mesothelioma, the specialist will also diagnose the mesothelioma cell type as:
- Epithelioid—The most common and most treatable type of mesothelioma.
- Sarcomatoid—The least common and most aggressive type of mesothelioma cells. These cells spread more quickly and are less treatable.
- Biphasic—When the tumor contains both sarcomatoid and epithelioid cells. The prognosis is better if there are more epithelioid cells present than sarcomatoid.
Because multiple cancers can appear similar to mesothelioma, such as lung cancers or a glandular cancer known as adenocarcinoma, it is vital that a sufficient sample is analyzed. Too small of a sample could result in a wrong diagnosis.
Whether your doctor extracts fluid for a cytology or a tissue sample for a histology, you should be prepared for additional tests and even surgery. It is vitally important you receive a correct diagnosis. With the margins of error present in both types of needle biopsy, seeking a second opinion from a mesothelioma specialist is highly recommended.
What to Expect During a Needle Biopsy
Both types of needle biopsies discussed are non-surgical, non-invasive procedures. You will be able to remain awake and will not need to stay overnight in the hospital. Your doctor will use a local anesthetic to numb the area where he or she intends to insert the needle. After the area is numb, the doctor will insert the needle to collect the sample and/or drain the fluid, depending on your specific case.
The procedure does not take long. After your doctor completely drains the fluid and collects a sample, the area will be cleaned and bandaged and you will be able to go home.
Needle Biopsy Risks
Because needle biopsies require no incisions and are such quick procedures, few patients encounter complications.
However, risks may include:
- Slight discomfort at the needle insertion site
- Slight bleeding from a pricked blood vessel
- A small possibility that the needle pokes a hole in your lung
If the needle pokes a hole in your lung, it results in air build-up between the lung and chest wall—you may not even feel it and it often corrects itself on its own. In the very rare case of a larger hole, a part of the lung could collapse, requiring treatment. To repair it, doctors place a catheter between the lungs and use it to suck out the air, allowing the lung to re-expand.
The largest risk that patients need to concern themselves with is that a needle biopsy may provide a less than reliable diagnosis, requiring patients to pursue further testing and surgery.
Benefits of Needle Biopsies vs. Surgical Biopsies
There are numerous benefits to getting needle biopsies rather than a surgical biopsy:
- Speed: The needle biopsy procedure is very quick and produces fast results.
- Minimally Invasive: Needle biopsies are a less invasive procedure than open surgery and easiest on the patient. A less invasive procedure is especially beneficial if the patient’s health makes surgery and general anesthesia risky.
- Fast Recovery: Because needle biopsies are such a gentle procedure, they require next to no recovery time for the patient.
Getting a Second Opinion from a Mesothelioma Specialist
As mentioned throughout the information above, while needle biopsies are convenient and sometimes your only safe option, it is extremely important that you seek a second opinion from a mesothelioma specialist. Because there is so much room for confusion between mesothelioma and other types of cancer, and since needle biopsies often fail to collect sufficient tissue samples for definitive results, you need to make sure you receive a proper diagnosis.
Without a proper diagnosis, you cannot pursue correct treatment, which could cost you precious time and even your life. If you need help understanding your recent diagnosis or finding a specialist near you, please contact our Patient Advocates today.