biopsying

Biopsying is the process of obtaining tissue or cells from a living body for diagnostic examination. It is used to diagnose diseases, characterize lesions, and guide treatment. Biopsies can be performed on many tissues, including skin, breast, liver, kidney, prostate, lymph nodes, bone, and the gastrointestinal tract. The collected specimen is examined by a pathologist, often after histological processing and sometimes with immunohistochemical or molecular tests.

Common methods include fine-needle aspiration (FNA), which uses a thin needle to extract cells; core needle biopsy (CNB), which uses a larger bore needle to obtain a tissue core; incisional biopsy, removing only a portion of a lesion; and excisional biopsy, removing the entire lesion. Punch biopsies are used for certain skin conditions. Many biopsies are guided by imaging such as ultrasound, computed tomography (CT), or magnetic resonance imaging (MRI) to target the correct area and reduce risks.

The procedure is typically performed under local anesthesia and is usually outpatient. Aftercare involves wound care and monitoring for bleeding or infection. Pathology processing yields cytology or histology slides; additional testing such as immunohistochemistry, molecular tests, or flow cytometry may be requested to refine diagnosis or plan treatment.

Risks and limitations include bleeding, infection, pain, or injury to adjacent structures. False negatives can occur due to sampling error or interpretive factors, and tumor seeding is rare. Contraindications include uncorrected bleeding disorders or situations where the procedure would pose excessive risk; in such cases alternative diagnostic approaches may be considered.