Clinical Reasoning: A 72-Year-Old Woman With Rapidly Progressive Bilateral Hearing Loss.

A 72-year-old woman presented with rapidly progressive hearing loss and neuropsychiatric symptoms without other focal neurologic symptoms. Progressive sequential sensorineural hearing loss (SNHL) was demonstrated on serial audiology. A diagnostic approach to SNHL is reviewed. Lumbar puncture revealed elevated protein, low glucose, and pleocytosis with poorly differentiated cells, and a differential diagnosis is discussed. MRI of the brain revealed gadolinium enhancement within the internal auditory canals bilaterally as well as the left cochlea. Zic4 antibodies were present in serum and CSF. A malignancy workup revealed right axillary lymphadenopathy. Biopsy revealed poorly differentiated breast adenocarcinoma, with identical cells to those in the CSF. The patient was treated with intrathecal methotrexate with no effect on the patient's hearing. In this case, rapidly progressive SNHL was the presenting feature of widely metastatic breast adenocarcinoma with leptomeningeal carcinomatosis, highlighting the need to search for a central cause for this presentation.