The most accurate test is to take a tissue sample from the area in question. If a fluid-filled cyst is detected, a needle biopsy may be performed to extract a sample of the fluid for microscopic analysis.
Biopsy options:

• Needle biopsy: may be performed on solid lumps to obtain a small sample of tissue for analysis.
• Open surgical biopsy: This procedure will allow a sample or the entire lump to be removed and sent for analysis.