Abnormal branching of facial nerve with ossicular anomalies: report of two cases.

Two cases with almost identical anomalies of the facial nerve and ossicles were reported. The two girls, ages 9 and 14 years, with unilateral hearing loss underwent exploratory tympanotomy. A huge suprameatal spine and tumor-like swelling of the facial nerve at the tympanic portion as well as its abnormal branching at the pyramidal bend were noted; one of the branches of the facial nerve appeared on the surface of the temporal bone running through the tympanomastoid suture. The distal parts of the long process and lenticular process of incus were missing as if they were eroded by the swollen facial nerve, and the superstructure of the stapes also was absent. No anomaly was seen in any other part of their ears or bodies. This specific type of anomaly is considered rare and important in that surgeons may misdiagnose the swollen facial nerve as a tumor, resulting in facial nerve paralysis due to injury or unnecessary biopsy.