An auricular hematoma is a collection of blood underneath the perichondrium of the ear. Auricular hematoma typically occurs secondary to trauma. Auricular deformity, commonly known as "cauliflower ear" is the result of untreated or inadequately treated auricular hematoma.
Source: https://www.instagram.com/p/CbNuRKUMkua/?utm_medium=copy_linkNot rare. Quite common in grappling sports. Drain blood asap, several times, and long term damage will be minimal. Only when the blood calcifies, it's permanent.
I see this often although maybe not the same shape but as Nick has mentioned, this is a regular thing for grapplers and other combat sport athletes. Not understanding the rarity label unless it may be attributed to random hematomas?