Histology
Sometimes it is necessary to take a small sample of tissue for examination under a microscope in order to diagnose an illness.
Biopsy
A biopsy is a portion of a lump, mole or other affected tissue that is removed for examination. Sometimes, the whole lump, mole etc is removed (excision biopsy).
Fine Needle Aspiration (FNA)
A fine needle is inserted into the affected area and some cells are sucked up for examination.