Dear ce45, It is not uncommon for the results of a needle biopsy can come back inconclusive. When they take a specimen in a needle biopsy the amount of tissue that is obtained is only what can be extracted through the needle. If when all of the information is put together (your symptoms, the physical exam, the results of the films, the biopsy findings) there is still a degree of uncertainty about the results - additional tissue may be needed to be more certain of the findings.