What Is The Role Of Pathologist To Test The Nodule On The Neck?

Hello wanted to ask a question pertaining to my mother. she went to the doctor and they found a nodule on the side of her neck. they did a fine needle aspiration biopsy and sent it to the lab for testing. She called this week to check the results to only be told they have to send to a pathologist. Can you tell me what reasons would they send the labs to a pathologist