Ganglion Cyst

A ganglion cyst, also known as a Bible cyst, is a swelling that often appears on or around joints and tendons in the hand or foot. An apparent misnomer, the ganglion cyst is unrelated to the neural "ganglion" or "ganglion cell"; its etymology traces back to the ancient Greek γάγγλιον, a "knot" or "swelling beneath the skin", which extends to the neural masses by analogy. Hippocrates is generally credited with their description. The size of the cyst may vary over time, and can increase after activity. The average size of these cysts is 2.0 cm, but cysts of more than 5 cm have been excised. It is most frequently located around the dorsum of the wrist and on the fingers. The term "Bible cyst" (or "Bible bump") is derived from a common treatment in the past that consisted of hitting the cyst with a Bible or similarly large book. Striking the ganglion cyst with a large tome is usually sufficient to rupture the cyst, and re-accumulation is uncommon.