A biopsy is a procedure used to obtain a piece of tissue for further examination. It is usually done to rule out the suspected diagnosis of cancer. The tissue is usually examined by a pathologist, who is a doctor with specialized training in recognizing diseases at a microscopic level.
Biopsies can be performed via one of four methods: fine needle aspiration biopsy (FNAB), core needle biopsy, incisional biopsy and excisional biopsy.
Fine Needle Aspiration Biopsy
In fine needle aspiration biopsy (FNAB), a small needle is inserted through the skin to withdraw fluid along with cells from a mass. It is most often used in the diagnosis of breast tumors. It has the advantage of being a relatively quick, simple procedure that does not require an operating room or a great deal of special equipment. It can be performed in an office setting. Once the sample is obtained, it is analyzed immediately by a pathologist.
Core Needle Biopsy
The principles of core needle biopsy are similar to FNAB, but the biopsy needle is larger than that used for FNAB. The needle is inserted through the skin after administration of a local anesthetic. A core tissue sample is obtained of the mass and sent to be examined by a pathologist. The core needle biopsy is most often employed in solid breast masses but may be used for any mass that can be easily felt under the skin.
Incisional Biopsy
An incisional biopsy involves performing a skin incision and some dissection to access the mass to be biopsied. A significant portion of tissue is removed from the mass, but some diseased tissue is left behind. This procedure is performed under a local anesthetic. It is perhaps the least popular method of obtaining a tissue sample because of relative invasiveness of the procedure, which does not yield any more information than other methods of biopsy.
Excisional Biopsy
An excisiional biopsy involves complete surgical removal of the mass. No diseased tissue is left behind, so that this procedure can be a cure for benign masses and even some malignant conditions. This is often the method used to remove superficial masses. As with all biopsies, the sample is sent to the pathologist for analysis.
To perform biopsies on internal organs, special instruments may be required, such an endoscope to perform a colon biopsy or an ultrasound-guided biopsy of the prostate.
References
- "Advanced Surgical Recall". Blackbourne, L. 2004
- "Bailey & Love Short Practice of Surgery". Russel, R.C.G., Williams, N., Bulstrode, C. 2009
