Core Biopsy
The core biopsy is a less common diagnostic test for parotid tumors. This test is almost never done as it takes a large sample and for most tumors would risk spreading tumor cells into the wound, which would be a serious problem if a person has a pleomorphic adenoma or a malignant tumor.
This test is only done for obviously inoperable tumors, if the physician is unable to determine the tumor type through a FNA, or if the FNA suggests the patient may have lymphoma.
In that case, there may be a need for more tissue, and a core biopsy would be done to avoid doing an open procedure; however, there is also more risk to the facial nerve with a core biopsy, and it is generally only used in rare circumstances.