What are the different methods by which biopsy specimens can be obtained according to the chapter?

Biopsy specimens can be obtained through several methods: needle withdrawal (aspiration), a small punch of the skin, endoscopy, and surgical removal of a tumor or node. Additionally, liquid biopsies can analyze cancerous cells or tumor DNA in circulating blood.

Biopsy is the process of removing tissue for microscopic examination, and it can be performed using various techniques. These include needle withdrawal (aspiration) to extract fluid, using a small punch to sample skin, conducting endoscopy for internal examination, and surgically removing tumors or nodes. Liquid biopsies are also emerging as a method for diagnosing cancer by analyzing circulating cancerous cells or tumor DNA in the blood.