Solitary Plasmacytoma of the Zygoma in a 70-Year-Old Nigerian: A Case Report and Review of Literature

Purpose: Solitary bone plasmacytoma [SBP] is a localised variant of plasma cell tumor which commonly affects the axial skeleton but rarely found in the maxillofacial region. We hereby report an unusual case of solitary plasmacytoma of the right zygomatic bone in a 70-year-old Nigerian. Case Report: The patient presented with a painless right zygomatic swelling of 2 years duration. Examination showed that the swelling was of mixed consistency [mostly bony but firm in some areas] and it measured about 8 × 8 cm. Radiographic examination revealed an osteolytic lesion over the right zygoma with involvement of the apex and lateral wall of the antrum. An initial working diagnosis of ossifying fibroma was made and the patient was scheduled for surgery. Histological staining with H & E and immunohistochemistry of the surgical specimen however confirmed a diagnosis of SBP. Serum monoclonal protein and Bence Jones proteinuria was negative throughout the follow up period. Conclusion: SBP of the maxillofacial region is amenable to surgery combined with postoperative radiotherapy. However, prognosis can be worsened with tumor recurrence or dissemination into MM. Thus patients with SBP must be closely followed up after treatment so that immediate therapeutic steps can be taken if recurrence or systemic dissemination is encountered.