Malignant lymphoma is primarily a disease of interest to haematologists, but it occasionally presents a problem for otorhinolaryngologists. Sinonasal lymphomas are rare and potentially radiocurable malignant neoplasms. At initial presentation, the disease is most often localized in the sinonasal region and, with rare exceptions, the dominating cytohistological type is the immunoblastic sarcoma (B-cell type), previously termed reticulum cell sarcoma. The clinical manifestations may mimic more common and benign conditions and the diagnosis may be difficult. The present paper, emphasizes the need for biopsy to be performed early and carefully even in the case of apparently benign lesions.