Does anyone know what this is? I've had it for a year now. It's under the skin, and it's leathery and thick on top. I feel like it's a cyst, but just want confirmation.

31 11

47 42

65 42

28 11

52 43

40 22

52 45

73 41

28 12

72 50

33 42

40 41

57 22

59 21

69 46

52 43