Extranodal natural killer/T-cell lymphoma presenting as cavernous sinus syndrome.

Extranodal natural killer (NK)/T-cell lymphomas are rare, highly aggressive tumors of the central nervous system (CNS) that commonly affect the nasal cavity or paranasal sinuses. NK/T-cell lymphomas are associated with a poor prognosis, as they exhibit a wide range of unique clinical presentations and neuroimaging findings that are currently difficult to detect. Pathological examination is considered to be more reliable for defining the pathological entity of NK/T-cell lymphoma. Early testing for fluorodeoxyglucose (FDG)-positron emission tomography combined with computed tomography may improve the evaluation of lymphomas, which have been known to display avid FDG uptake. The authors herein report a case of NK/T-cell lymphoma presenting with cavernous sinus syndrome involving the CNS via direct extension from the nose. NK/T-cell lymphomas are very aggressive, with an unfavorable clinical outcome, and the optimal therapy has not yet been clearly defined.