Objective: Although the Working Formulation is commonly used to classify NHL in Japan, it has been recognized as imperfect for primary extranodal lymphoma, especially for patients with sinonasal disease because of their histological characteristics. The present study investigated the clinical characteristics and the prognosis of sinonasal lymphomas according to REAL classification.
Methods: Fifty-three patients with non-Hodgkin's malignant lymphoma (NHL) of the sinonasal tract were treated between 1981 and 1997. The age at clinical presentation was from 10 to 84 years (mean, 52.4 years). According to the Ann Arbor system, there were 30 patients with Stage IE, 13 with Stage IIE, 4 with Stage IIIE, and 6 with Stage IVE lymphomas. Twenty-two patients (41.5%) had B symptoms. The primary sites were the nasal cavity (67.8%), maxillary sinus (20.8%), ethmoidal sinus (9.4%), and frontal sinus (1.9%). The survival data was calculated by Kaplan-Meier method. Statistical analysis was performed with a generalized Wilcoxon method.
Results: All of the lymphomas showed a diffuse growth pattern. Based on the origin of the tumor cells, the authors classified NHL of the sinonasal tract into five groups with the REAL classification of Japan: diffuse large B-cell lymphoma (22.6%), peripheral T-cell lymphomas (15.1%), angiocentric lymphoma (35.9%), other lymphomas and unclassified types. Of 53 patients, 39 (73.6%) received chemotherapy and radiotherapy, eight patients received chemotherapy alone, and four patients received radiotherapy alone. The cumulative 5-year survival rates were 28.5% for all of the types, 55.0% for diffuse large B-cell lymphoma, 33.3% for peripheral T-cell lymphoma, and 19.7% for angiocentric lymphoma. Results suggest that conventional combined treatment (CHOP chemotherapy+radiotherapy) is ineffective for NHL of the sinonasal tract, and especially so for NHL in the nasal cavity, NHL with tumor cells with positive T-cell markers, NHL further than Stage IIE and NHL with B symptoms.
Conclusion: (1) In light of this ineffectiveness, new therapies must be developed to improve patient outcome instead of the conventional combined treatment; (2) REAL classification is clear and useful for sinonasal lymphomas in Japan.