Sinonasal T-cell lymphomas: A clinicopathologic study of a possibly distinct entity

Background: Most cases of sinonasal lymphomas reported in the literature wh ich show positive expression for Epstein-Barr virus are CD2+, CD3-, CD43+ a nd CD56+, and also show a germ-line T-cell receptor genotype. Five-year sur vival is usually around 50%. We report a group of patients with T-cell sino nasal lymphoma that showed distinct immunophenotypic and molecular profiles and a more aggressive behavior. Patients and Methods: Nineteen cases representing approximately 75% of sino nasal lymphoma diagnosed and treated at our institution between 1988 and 19 97 were studied. They comprised 12 males and 7 females, with an age range o f 10 to 73 years (median 46 years). The remaining cases (about 25%) were B- cell lymphomas. The morphology of the cases was evaluated together with a l imited immunophenotyping. In situ hybridization for EBV mRNA was performed in 18 cases. Polymerase chain reaction (PCR) for T-cell receptor (TCR) gene rearrangement was performed in 15 cases. Clinical follow-up information wa s available on 14 patients. All cases showed a pattern of large-cell lympho ma, and three exhibited an immunoblastic morphology. The tumors showed exte nsive soft tissue invasion, necrosis and ulceration. While perineural invas ion was a prominent feature, perivascular invasion was not noticed. Results: Seventeen tumors (84%) were CD3 positive. PCR analysis showed TCR gene rearrangement in 7 of 15 cases (46%). Fifteen cases (79%) were positiv e for EBV. The 14 patients with available clinical information had extensiv e local diseases, with stages ranging from IE to IIIE, where none showed po sitive bone marrow involvement. The 14 patients received chemotherapy with or without radiation therapy. Ten of the 14 patients (71%) died of the dise ase after a median of seven months, including all seven patients with posit ive TCR gene rearrangement. Conclusion: Our findings suggest that sinonasal T-cell lymphoma represents a heterogeneous group of diseases with different phenotypic, genotypic and biological characteristics. Cases that show TCR gene rearrangement may repr esent a more aggressive subtype of the disease.