CNS RELAPSE OF NHL MASQUERADING AS MILLER FISHER SYNDROME

A 60 year old man with previous history of NHL (Non Hodgkin Lymphoma) presented with progressive dysphagia and dysarthria over two weeks.He had bilateral lower motor neuron facial weakness, diplopia on lateral gaze and nystagmus on examination. Working diagnosis was Miller Fisher syndrome and he was commenced on intravenous immunoglobulins. Subsequently he developed shortness of breath due to inability to maintain airway secondary to bulbar dysfunction. Review of MRI brain revealed enhancement of basal meninges with contrast suggestive of entrapment of cranial nerves. CSF showed 760 lymphocytes and elevated protein at 1.2 g/L. Immunophenotyping revealed the lymphocytes to be of Natural Killer (NK) cell origin leading to diagnosis of relapse of lymphoma involving CNS. He was diagnosed ten months ago with extranodal nasal NK/T cell lymphoma involving paranasal sinuses which is a rare subtype of NHL and is associated with Epstein-Barr virus. He was treated with four cycles of SMILE chemotherapy and local radiotherapy and had achieved complete remission as evidenced by a negative PET CT scan three months ago. This case stresses the importance of considering CNS relapse as a differential in patients presenting with neurological symptoms and history of lymphoma even though CNS relapse is rare for NHL (2.8%).