B-cell lymphoma of the brainstem with central neurogenic hyperventilation.

Non-Hodgkin's lymphoma of the brainstem is a rare entity. Central Neurogenic Hyperventilation (CNH), an associated manifestation of this disease, is an even rarer event. We report a case of an immunocompetent individual who presented to us with tachypnea and facial nerve palsy. Neuroimaging showed a Cerebellopontine angle tumour which on histopathology showed feature consistent with a Non-Hodgkin's B-Cell Lymphoma. The patient went on to develop severe respiratory alkalosis with findings consistent with CNH. Chemotherapy with Methotrexate was started and high dose Dexamethasone was added to the regimen a month later. Radiologically, the tumour size decreased by 50% but the patient's clinical condition deteriorated. He eventually expired due to cardiopulmonary arrest. Some common clinical presentations of this disease and various diagnostic modalities and treatment options available to such patients are discussed.