Ultrasound can be used to guide a needle into a cyst (eg Baker’s cyst, popliteal cyst, ganglion cyst in the wrist, hand or foot) or bursa (eg olecranon bursa)

Local anaesthetic can be injected initially into the skin to make the skin over the cyst or bursa numb. Then the needle can be guided into the cyst or bursa. Then the fluid contents of the cyst or bursa can be aspirated out. This can be sent to the pathology company to be tested for gout, infection or other diseases. The pathology company will send the results directly to the referring doctor.

Sometimes, after the aspiration is completed, steroid and local anaesthetic medication can be injected into the cyst or bursa as treatment. Sometimes the wall of the cyst is fenestrated (ie punctured multiple times with a fine needle) to help prevent the cyst from recurring.