title: Sinonasal T-Cell lymphomas: A clinicopathologic study of a possibly distinct entity.
abstract: BACKGROUND
  Most cases of sinonasal lymphomas reported in the literature which show positive expression for Epstein-Barr virus are CD2+, CD3-, CD43+ and CD56+, and also show a germ-line T-cell receptor genotype. Five-year survival is usually around 50%. We report a group of patients with T-cell sinonasal lymphoma that showed distinct immunophenotypic and molecular profiles and a more aggressive behavior.
  
  
  METHODS
  Nineteen cases representing approximately 75% of sinonasal lymphoma diagnosed and treated at our institution between 1988 and 1997 were studied. They comprised 12 males and 7 females, with an age range of 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 limited 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 was available on 14 patients. All cases showed a pattern of large-cell lymphoma, and three exhibited an immunoblastic morphology. The tumors showed extensive soft tissue invasion, necrosis and ulceration. While perineural invasion 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 positive for EBV. The 14 patients with available clinical information had extensive local diseases, with stages ranging from IE to IIIE, where none showed positive bone marrow involvement. The 14 patients received chemotherapy with or without radiation therapy. Ten of the 14 patients (71%) died of the disease after a median of seven months, including all seven patients with positive TCR gene rearrangement.
  
  
  CONCLUSIONS
  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 represent a more aggressive subtype of the disease.
authors.affiliation: Departments of Pathology and Oncology, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia.
authors.forename: W A
authors.initials: WA
authors.lastname: Mourad
authors.forename: M
authors.initials: M
authors.lastname: Ahktar
authors.forename: S H
authors.initials: SH
authors.lastname: Khalil
authors.forename: F
authors.initials: F
authors.lastname: Al Dayel
authors.forename: M A
authors.initials: MA
authors.lastname: Ali
authors.forename: A
authors.initials: A
authors.lastname: Ezzat
authors.forename: A
authors.initials: A
authors.lastname: Rostom