Abstract
Paranasal sinus lymphoma (PNL) is a rare presentation of extranodal non-Hodgkin lymphoma (NHL) with a natural history different from other types of lymphoma. The maxillary sinus is the most common paranasal sinus involved in NHL. Involvement of the central nervous system (CNS) is a rare complication of PNL. In this case report, we present a case of diffuse large B cell lymphoma (DLBL) that developed in the left maxillary sinus and relapsed as a left frontal brain mass after four years of disease remission.