Spinal cord compression due to a solitary, bulky plasmacytoma of posterior mediastinum.

Solitary plasmacytoma is a rare clonal plasma cell tumor, representing 2-5% of plasma cell disorders. The standard treatment is local radiotherapy. However, in some cases, its use is limited by the size and/or location of the mass. Systemic chemotherapy may be a useful therapeutic alternative. We describe a case of a 27-year-old male with a bulky solitary plasmacytoma arising in the posterior mediastinum, causing spinal cord compression. Radiotherapy was considered risky as the mass was located in the heart and left lung fields. Systemic treatment was given. After the first cycle of cyclophosphamide, bortezomib, and dexamethasone (VCD), the patient attained full neurological recovery. After four VCD cycles, complete remission was achieved. Autologous stem cell transplantation was given as consolidation therapy. At 3 months post-transplantation, the patient is in full clinical recovery and complete metabolic remission on 18FDG PET-CT. Although infrequent, plasma cell disorders must be considered in adult patients with a bulky tumoral mass in the posterior mediastinum. PET-CT is the whole-body imaging technique of choice to detect SP, to evaluate response to treatment and during follow-up.