What is a ganglion ? ​

Ganglion cysts are lumps that most commonly develop in the wrist. They're typically round or oval and are filled with a jelly-like fluid. Ganglion cysts are noncancerous lumps that most commonly develop along the tendons or joints of your wrists or hands. They also may occur in the ankles and feet.

Explanation:

A non-cancerous lump, often on the tendons or joints of wrists and hands.

The cause of ganglion cysts is unknown

segmentation=endoskeleton=backbone=coelom=tissues