Background: Plasma cell granuloma is a rare benign lesion which is found most frequently in the lungs, and a few cases have been described in the head and neck. In the middle ear and mastoid, a case of plasma cell granuloma was reported by Benton et al.
Methods and results: A 24-year-old woman was seen with a 7-month history of otalgia and decreased hearing. A computed tomographic (CT) scan showed a soft tissue mass occupying most of the mastoid bone. The mass and the contiguous dura were enhanced homogeneously on magnetic resonance imaging (MRI) scan. Microscopic examination showed plasma cell aggregates mixed with other inflammatory cells and Russell's bodies in a fibrous stroma. Immunoperoxidase studies revealed intracytoplasmic kappa and lambda light chains, and the lesion was confirmed as non-neoplastic and of polyclonal origin (ie, plasma cell granuloma). The patient was treated with conservative surgical excision (a canal-down mastoidectomy) and postoperative radiotherapy (5,040 cGy in 28 fractions) and remains free of disease 1 year after treatment.
Conclusions: A case of plasma cell granuloma is reported, and we believe this is the second case report of plasma cell granuloma affecting the temporal bone.