Double Vision May Mean Double Trouble

Abstract

INTRODUCTION: Leptomeningeal metastasis (LM) is a rare neurologic complication of systemic malignancies due to tumor invasion into the subarachnoid space. Seeding of the leptomeninges is uncommon affecting approximately 5% of patients with solid organ tumors. LM typically presents months to years after primary tumor diagnosis and treatment. Neurologic manifestations are rarely the presenting symptom of solid tumors metastasis to the leptomeninges. We describe a case of lung cancer presenting as multiple cranial neuropathies due to leptomeningeal metastases. CASE PRESENTATION: A 56 year old man with history of depression, hepatitis C and a 40 pack year smoking history presented with eight days of headache, hearing loss, and two days of diplopia. Interestingly, these symptoms started two months after painting an attic infested with bats. His exam was notable for 3mm pupils bilaterally, slow adduction and ptosis of the right eye, normal visual fields and left greater than right sided hearing loss. Computer tomography (CT) and magnetic resonance imaging (MRI) of the head were performed and showed no acute abnormality. Lumbar puncture was significant for total cell count of 184/cumm with 84% lymphocytes. Flow cytometry consisted of predominantly T-cells with an unremarkable immunophenotype. Protein was elevated at 154 mg/dL (15-45mg/dL) with glucose of 55 mg/dL (40-70mg/dL). Despite empiric treatment for fungal and bacterial, infections his hearing loss worsened and he developed additional cranial neuropathies over the next several days. Chest CT was performed due to concern for possible paraneoplastic syndrome, and showed a 2.6 by 1.2 cm spiculated mass in the right upper lobe (Figure 1). CT guided biopsy confirmed adenocarcinoma of lung and repeat MRI of the brain showed nodular leptomeningeal metastatic disease (Figure 2). Cerebrospinal fluid cytology was suggestive of malignancy on final interpretation as well. DISCUSSION: When tumor cells gain access to the cerebral spinal fluid and the subarachnoid space, they can invade the leptomeninges at multiple locations producing a wide range of symptoms. The most frequent symptoms are headache, altered mental status and diplopia; similar to our patient. However, our case is unique because our patient presented with neurologic symptoms from LM prompting the diagnosis of lung cancer. CONCLUSIONS: There is limited information in the literature regarding LM as the presenting symptom of primary malignancies. This case highlights a rare presentation of a common disease. Clinicians should keep in mind that multifocal neurologic manifestations may be the presenting symptom of otherwise asymptomatic lung cancers.