A soft tissue biopsy is a diagnostic procedure where a small sample of tissue is removed from the body for microscopic examination. The body’s “soft tissues” include a wide range of structures, such as skin, fat, muscles, tendons, and blood vessels. This procedure is performed to investigate abnormalities like lumps, tumors, or inflammation.
Reasons for a Soft Tissue Biopsy
A physician may recommend a soft tissue biopsy to investigate an unexplained growth, swelling, or area of inflammation discovered during a physical exam or on an imaging study. A key reason for a biopsy is to diagnose whether a mass is benign, meaning non-cancerous, or malignant, indicating cancer.
Beyond cancer detection, a biopsy can identify the specific cause of infections, such as those caused by bacteria or fungi. It is also used to diagnose certain inflammatory conditions, including autoimmune disorders that can affect soft tissues. In cases where a rare type of cancer known as a soft tissue sarcoma is suspected, a biopsy is necessary to confirm the diagnosis. The procedure provides definitive answers that imaging and blood tests alone often cannot.
Common Biopsy Techniques
The method chosen for a soft tissue biopsy depends on the size, depth, and location of the abnormality. One common approach is a needle biopsy, which is minimally invasive. This category includes fine-needle aspiration (FNA), where a very thin needle extracts fluid and cells, and core needle biopsy (CNB), which uses a larger, hollow needle to remove a small, cylindrical piece of tissue. CNB provides a more substantial sample than FNA, often increasing diagnostic accuracy.
For larger or less accessible masses, a surgical biopsy may be performed. An incisional biopsy involves a surgeon making a cut in the skin to remove only a portion of the suspicious tissue. This provides a generous sample for the lab to analyze while leaving the bulk of the mass intact.
In other situations, a surgeon may perform an excisional biopsy, a procedure where the entire lump or abnormal area is removed. This technique serves both a diagnostic and therapeutic purpose, as it can simultaneously confirm the diagnosis and treat the issue by removing the entire mass.
The Biopsy Procedure Experience
You may be instructed to stop taking certain medications, particularly blood thinners, for a period before the procedure to reduce bleeding risk. If sedation is planned, you might be asked to fast from food and drink for several hours beforehand and arrange for someone to drive you home.
During the biopsy, the site will be cleaned, and a local anesthetic is injected to numb the area, so you will likely feel pressure but not sharp pain. For some procedures, especially more invasive ones, intravenous conscious sedation may be administered to help you relax. The duration varies depending on the type of biopsy, with some taking less than half an hour.
After the procedure, a sterile dressing or bandage will be applied to the site. It is common to experience some mild soreness, tenderness, or bruising in the area for a few days, which can often be managed with over-the-counter pain relievers. Your healthcare provider will give you specific instructions on how to care for the wound and any temporary restrictions on your activities.
Understanding the Pathology Report
The tissue sample collected during the biopsy is sent to a laboratory, where a specialized doctor called a pathologist examines it under a microscope. The pathologist prepares a detailed report of their findings, which is then sent to the physician who ordered the test.
The pathology report will classify the tissue as benign, malignant, or inconclusive. An inconclusive result means the sample was not sufficient to make a clear diagnosis, and another procedure might be necessary.
Your doctor will schedule a follow-up appointment to discuss the pathology report with you in detail. Based on this confirmed diagnosis, you and your doctor will then determine the next steps, whether that involves further treatment, monitoring, or no action at all.