SEER is an authoritative source of information on cancer incidence and survival in the United States. SEER currently collects and publishes cancer incidence and survival data from population-based cancer registries covering approximately 28 percent of the U.S. population.
Predominantly extranodal, characterized by a broad morphologic spectrum. The infiltrate is often angiocentric, with prominent necrosis and vascular destruction. It is designated NK/T (rather than NK) because while most cases appear to be NK cell neoplasms, (EBV+ CD56+), rare cases show EBV+ CD56- cytotoxic T-cell phenotype.
Extranodal NK/T cell lymphoma almost always shows an extranodal presentation. Some cases may be accompanied by secondary LN involvement although rare instances of primary LN disease in the absence of extranodal involvement has been reported.
Extension to adjacent tissues such as the nasopharynx, paranasal sinuses, orbit, oral cavity, palate, and oropharynx are possible. At presentation, the disease is often localized to the upper aerodigestive tract.