FIGURE 120.3 Hair tourniquets (Reprinted with permission from Fleisher GR, Ludwig S, Baskin MN Atlas of Pediatric Emergency Medicine Philadelphia, PA: Lippincott Williams & Wilkins; 2004.) Ganglion A ganglion is a cystic outgrowth of the synovial lining of a tendon sheath or joint capsule Common locations of ganglions include the dorsal or volar surface of the wrist (usually on the radial side), the dorsum of the foot, and near the malleolus of an ankle ( Fig 120.4 ) Occasionally, a flexor tendon sheath ganglion may present on the palmar surface of the hand at the base of a digit The cause is believed to involve prior trauma that causes partial disruption of the synovium and subsequent herniation of synovial tissue The cysts are soft, slightly fluctuant, and transilluminate Most are painless or are only mildly uncomfortable However, those on the foot or ankle may cause pain when shoes are worn Ganglions rarely require emergent intervention Elective surgical excision with obliteration of the base is indicated only if function is impaired or the lesion is of cosmetic significance However, recurrent rates after excision are as high as 20% Striking the cyst with a heavy object, a folk remedy, should be strongly