The petrified auricle: comments on ossification, calcification and exostoses of the external ear.

The petrified auricle is a clinical entity in which the auricle, in part or total, has become stone-hard and moves as a rigid unit. This uncommon condition is most often due to ectopic calcification of the auricular cartilage. It may occur as a result of local trauma, in association with various systemic diseases such as Addison's disease, hypopituitarism, thyroid or parathyroid disorders, or following radiation therapy. Auricular ossificans (ectopic ossification) is a rare phenomenon in which the rigidity of the petrified ear is due to replacement of the elastic cartilage by bone. In the literature there are presently nine cases documented histologically. Two more cases are reported here. In most cases, the auricular changes are preceded by acute, severe hypothermia (frostbite). Exostoses of the external auditory canal is another disease of the external ear in which the proliferation of bone follows chronic mild hypothermia of the external auditory canal caused by exposure to cold water while surfing. It is postulated that if surfers who have developed exostoses of the external auditory canal from the cold water continue to enjoy such littoral activities, ossification of the auricle may also occur.