Pseudocyst of the auricle

Pseudocyst of the auricle, also known as auricular pseudocyst, endochondral pseudocyst, cystic chondromalacia, intracartilaginous auricular seroma cyst, and benign idiopathic cystic chondromalacia, is a cutaneous condition characterized by a fluctuant, tense, noninflammatory swelling on the upper half of the ear, known as the auricle or pinna. Pseudocysts of the auricle are nontender, noninflammatory cystic lesions that progress over a 4- to 12-week period, ranging from 1 to 5 cm in diameter.

Source: Wikipedia — Pseudocyst of the auricle (CC BY-SA 4.0)