[Recent advances on extranodal NK/T-cell lymphoma of nasal type]

Extranodal NK/T-cell lymphoma, nasal type (ENKT), is a distinct clinicopathologic disease, common among East Asia and Latin America population. Clinically, it frequently occurs in middle-aged men. It predominantly occurs in the nasal or paranasal areas and less frequently in the skin. The main clinical features are nasal congestion, sore throat, dysphagia and epistaxis, due to a destructive mass involving the midline facial tissues. The pathogenesis of ENKT remains uncertain. It is thought that Epstein-Barr virus (EBV) may play a role in the development of this entity. Pathologically, lymphoma cells exhibit angioinvasion, angiodestruction and coagulative necrosis. It has unique characteristics including the expression of cytoplasmic CD3, CD56 and cytotoxic molecules such as TIA-1, and is positive for EBV in situ hybridization. The overall prognosis of this disease is poor because of frequent relapse or resistance to treatment. Although several studies have explored the treatment of ENKL in recent years, the optimal therapy has still not been found. Due to the highly aggressive features of tumors, every endeavor has been made to investigate factors associated with poor outcome. In this review, the recent advances on cause and pathogenesis, clinical manifestations and staging, pathologic characteristics, diagnosis and differential diagnosis, therapy and prognosis of ENKL are summarized.