Extranodal natural killer/T-cell lymphoma nasal type with central nervous system involvement mimicked tuberculous meningitis: A case report

RATIONALE: Neurologic deficits are rare in patients with extranodal natural killer/T-cell lymphoma (NKTL), nasal type. We present a case that was initially suspected as tuberculous meningitis, but later diagnosed as central nervous system metastasis of NKTL, nasal type, which has never been published previously. PATIENT CONCERNS: A 55-year-old Chinese man presented with persistent headache and fever. The initial head computed tomography and magnetic resonance imaging (MRI) scan was normal. Low glucose, elevated protein, and pleocytosis of cerebral spinal fluid led to a diagnosis of tuberculous meningitis. The patient did not respond to anti-tuberculosis treatment, and his symptoms aggravated. MRI showed abnormal lesions in the right hemisphere and a lesion in the maxillary sinus region. DIAGNOSIS: Endoscopic biopsy of the maxillary lesion showed features consistent with NKTL. Positron emission tomography revealed a hypermetabolic mass involving the right maxillary sinus and brain. INTERVENTIONS: The patient received chemotherapy. OUTCOMES: The patient died 30 days after chemotherapy. LESSONS: Lymphoma of the nasal cavity and paranasal sinuses is extremely rare and may be easily misdiagnosed. Nasal NKTL metastasis should be considered when a patient presents with symptoms of leptomeningeal involvement.