Extramedullary Plasmacytoma of the Frontal Sinus: Case Report and Turkish Literature Review

Solitary extramedullary plasmacytomas (EMPs) are nonepithelial neoplasms of plasma cell origin categorized among non-Hodgkin lymphomas, without the bone marrow involvement and systemic spread seen in multiple myeloma. They are uncommon tumors comprising 3% of all plasma cell neoplasias. Although they usually occur in the upper respiratory tract, only 1 case of EMP localized to the frontal sinus has been reported in the English literature. We present in this report a rare case of EMP originated from the left frontal sinus leading to left eyeball proptosis and movement restriction. A survey of sinonasal EMPs in the Turkish literature is reported, as well. Paranasal computerized tomography and magnetic resonance imaging of a 69-year-old female who presented with left eyeball proptosis and left-sided headache revealed a solid mass in the left frontal sinus. Histopathological analysis of the completely excised mass supported the diagnosis of plasmacytoma. The definitive diagnosis of solitary EMP was confirmed with further investigations at hematology and oncology clinics. The patient was treated with surgery followed by local radiotherapy to the head and neck region, and she was disease-free at her 1-year follow-up. Treatment of sinonasal EMP is surgery alone or surgery combined with radiotherapy. Long-term follow-up is a requisite for systemic control because of the disease's high potential to transform into multiple myeloma.