A Curious Case of Crystal Deposit Disease in the Petrous Bone

Abstract

Crystal deposit disease is a rare disorder with benign dense soft tissue calcium containing accumulations presenting as pseudogout or tumoral calcinosis. It rarely affects the head and neck region and even less to the petrous bone. We describe a case of para-articular tumoral calcinosis involving the external auditory canal wall in close proximity to the temporomandibular joint with extension towards the middle cranial fossa floor in a 73-year-old man presenting with otalgia and progressing mixed hearing loss. Subtotal petrosectomy with obliteration of the middle ear and mastoid was done with complete removal of the lesion. We discuss the course, treatment and final pathology with possible explanations for the pathophysiology in this particular case. Although tumoral calcinosis is uncommon, this entity should be considered in the differential diagnosis when an osteogenic temporal lesion is seen on computed tomography or magnetic resonance imaging. The treatment for this benign tumor includes complete excision of the lesion in symptomatic cases. Proper evaluation including anamnesis of the family history and previous trauma as well as serology should be done. The exact etiology and classification of crystal deposit diseases require further study.