Primary Sinonasal Lymphoma: A Rare Cause of Cranial Neuropathies.

Primary sinonasal lymphomas are a rare type of non-Hodgkin lymphoma (NHL) with an overall incidence of about 1% of all head and neck cancers. Diffuse large B-cell lymphoma (DLBCL) is the most common type of NHL and it most commonly occurs in elderly men. The diagnosis of such a lymphoma is difficult because of its varied presentation, which usually occurs late after a significant mass effect has taken place. Symptoms vary significantly, from simply nasal obstruction or epistaxis to varied cranial neuropathies or the confusion seen with central nervous system (CNS) spread. Patients may present with a large orbital mass and proptosis. Therefore, emphasis should be placed on earlier detection by using appropriate imaging modalities to reveal such masses. A biopsy is necessary to confirm the diagnosis. The prognosis is scored by the International Prognostic Index. Staging scans with whole-body computed tomography (CT) with contrast and positron emission tomography-fluorodeoxyglucose (PET-FDG) are required to determine other areas of involvement. Treatment is with R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) with the case-dependent use of intrathecal chemoprophylaxis (methotrexate) to prevent CNS spread. Here, we present a case series of two patients who were found to have a primary sinonasal lymphoma of the DLBCL type. In both cases, the presenting symptoms were vague. A high index of suspicion is required to diagnose NHL early on, which portends the best chance of a successful outcome. This article seeks to emphasize the role of including primary sinonasal lymphoma as a differential in the presentation of unrelenting cranial neuropathies or facial mass.