The depth of a biopsy varies greatly depending on the type of biopsy and the location of the tissue sample. A common skin biopsy, such as a punch biopsy, typically removes tissue about 1.5 millimeters deep. However, other biopsies can be significantly deeper.
Types of Biopsies and Their Depths
- Punch Biopsy: This common skin biopsy uses a circular tool to remove a core of skin tissue, often reaching the deeper layers. The depth is usually around 1.5 mm, as noted in the provided text: "The amount of tissue removed is usually less than 4 millimetres in diameter and about 1.5 millimetres deep."
- Shave Biopsy: This technique removes a thin layer of skin tissue using a blade. It is generally less deep than a punch biopsy.
- Incisional Biopsy: This biopsy takes a sample of a larger area and goes deeper than a punch biopsy, removing a portion of the suspicious tissue. The depth will vary depending on the location and size of the lesion.
- Excisional Biopsy: This involves removing the entire abnormal area and surrounding tissue. The depth varies depending on the size and location of the lesion. Often, it's used when a wider or deeper portion of tissue is needed.
- Endoscopic Ultrasound-Guided Biopsy: This technique allows for deep and large biopsies, often used for lesions deep within the body like those in the stomach. The depth is determined by the location and size of the target tissue.
- Core Needle Biopsy (CT-guided): Used for deep-seated lesions, like in muscles, these biopsies utilize a needle to extract a sample. The depth can be significant, depending on the target tissue's location.
The depth of a biopsy is determined by the physician based on the clinical findings and the type of diagnosis needed. A larger sample and greater depth might be required if the doctor suspects a deeper lesion or a more extensive examination is needed. For example, examining tumors that may have grown into deeper skin layers often necessitates an excisional or incisional biopsy.
