Chondrosarcomas are mesenchymal, cartilaginous tumors more commonly found in the axial skeleton than soft tissues, but rarely arise in the skull base.1 Herein we present a case of a primary mastoid chondrosarcoma initially diagnosed as a facial nerve tumor and was later found to have infiltrated and replaced a segment of the nerve.
A man in his 60s presented with a 2-year history of gradual-onset right facial weakness leading to paralysis. He was initially treated with oral steroids for Bell palsy. Magnetic resonance imaging (MRI) showed a facial nerve tumor in the mastoid. At presentation, he denied hearing loss, tinnitus, imbalance, or other cranial nerve deficits. He had no other significant medical history. On examination, he had complete right facial paralysis and a nonpulsatile mass protruding through the inferior ear canal. Audiographic findings showed mild sensorineural loss at 4000 Hz, but were otherwise normal.