Facial nerve palsy produced by plasma cell granuloma.

There are many causes for peripheral facial nerve palsy, such as an isolated phenomenon occurring in a healthy person (Bell's palsy), a manifestation of a systemic illness, or a component of a more widespread neurological disease. Plasma cell granuloma is the proliferation of polyclonal, nonneoplastic plasma cells. Several cases have been reported in the literature in which plasma cell granulomas have affected the brain, lungs, gastrointestinal tract, kidneys, salivary glands, and skin. We report a case of peripheral facial nerve palsy produced by a plasma cell granuloma that was confirmed by histological and immunohistochemical studies.