If the scan shows that the disease does not appear to be getting better, you will have a fine needle aspiration (FNA), core needle biopsy, and/or an excisional biopsy to check the status of the disease. To collect an FNA, a small amount of tissue is withdrawn through a needle. To perform a core needle biopsy, a sample of tissue is removed using a hollow core needle that has a cutting edge. To perform an excisional biopsy, the affected area is completely removed by cutting it out.