Experience of radiotherapy in lethal midline granuloma with special emphasis on centrofacial T-cell lymphoma: a retrospective analysis covering a 34-year period.

Lethal midline granuloma (LMG) is characterized by progressive ulceration and destruction of the midfacial tissue. It occurs more frequently in Oriental than in Western populations. Because of the progress in clinical pathology and immunohistochemistry, most cases have been proven to be malignant lymphomas, especially of T-cell lineage. We describe 92 cases of lethal midline granuloma or centrofacial malignant lymphoma in the period 1959-1993. All received complete courses of radiotherapy. Twenty of them also received combination chemotherapy. Thirty-six cases had specimens available for immunohistochemical study; 25 (69%) of these had a T-cell phenotype, and 6 (17%) were of B-cell lineage. The dose to the nasal region was in the range of 3000-7500 cGy in 11-58 days, and to the neck 3000-6400 cGy in 11-48 days. The overall survival rate for the LMGs was 59.5% at 5 years and 56.2% at 10 years (Kaplan-Meier). Combined chemotherapy seemed not to improve the overall survival in this study (p = 0.63), but the patient number was too small to make a firm conclusion. Based on the results of this study, we recommend a dose of 4500-5000 cGy to the midfacial region, since a higher dosage did not improve the treatment results (p = 0.88). Irradiation has a definite role in good locoregional control of this disease. The recent clarification of the disease nature and the recognition of the background clinicopathological features should provide valuable information for future patient management and prospective studies.