Plasmacytoma of the mastoid bone: solitary and systemic

Plasma cell tumours of the mastoid are rare malignancies of haematological origin. Two patients are described with a plasma cell tumour in the mastoid bone. In one patient it concerned a solitary plasmacytoma of the bone and in the other a focus in the mastoid of a recently diagnosed multiple myelom a. Symptoms in these patients were non-specific. Computed tomography (CT) a nd magnetic resonance image (MRI) scanning showed a nonspecific space-occup ying lesion in the mastoid. The diagnosis was made on immunohistological ex amination, that showed diffuse sheets of monoclonal plasma cells in a clear matrix. When a plasmacytoma lesion is found multiple myeloma should always be excluded. Treatment in case of solitary plasmacytoma of the mastoid bon e consists of radiotherapy. In case of localization in the mastoid of multi ple myeloma the treatment consists of palliative chemotherapy.