Metastatic Intracerebral Plasmacytoma Treated with Radiation and Thalidomide, Dexamethasone with Cyclophosphamide Chemotherapy.

Intracerebral plasmacytoma is an extremely rare disease for which no treatment protocol has been established. The authors present a case of metastatic intracerebral plasmacytoma that was partially resected and treated with radiation therapy. For tumor recurrence, a combination chemotherapy regimen was initiated. A 48-year-old male patient presented with dizziness and memory loss. Conventional magnetic resonance imaging (MRI) of the brain revealed a multilobulated mass with enhancing cystic and solid components measuring 7 × 7 × 6 cm in the left frontal lobe. The patient had undergone subtotal gastrectomy and transverse colectomy 8 years before admission and had been diagnosed with extraosseous plasmacytoma. At the time of the current presentation, the patient underwent craniotomy for the parenchymal lesion. Partial tumor resection was performed. Histologic and immunohistochemical examinations confirmed the diagnosis of plasmacytoma. Fractionated radiotherapy was administered, and no enhancing mass was observed on follow-up MRI. One year after radiotherapy, tumor recurrence was observed in a different area of the cerebral parenchyma. Combination thalidomide, dexamethasone, and cyclophosphamide chemotherapy was administered. After three cycles of chemotherapy, the tumor was well controlled on MRI. Hereafter, two more times of tumor recurrence occurred in the other sites of the cerebral parenchyma, but with chemoradiation therapy, the tumor was well suppressed. The findings of this case suggest that the cerebral parenchyma can be one of the metastatic sites for extraosseous plasmacytoma. In addition, combination chemotherapy with thalidomide, dexamethasone, and cyclophosphamide may be a useful treatment option for intracerebral plasmacytoma.