Primary Leptomeningeal Lymphoma Presenting as Low Back Pain and Dementia: A Case Report

Abstract

Primary leptomeningeal lymphoma (PLL) is an extremely rare condition, with only a handful of cases reported in literature. Most often, these are misdiagnosed as other disease entities that are more commonly observed in practice. Currently, there are no clinical algorithms that may guide clinicians to clinching a diagnosis of PLL. This paper discusses a remarkable case of PLL presenting with atypical symptoms namely dementia and low back pain. This is a case of an apparently well adult male who initially presented with low back pain that was treated for two years as a case of lumbar disc herniation. This developed into lower extremity weakness and was subsequently followed by dementia and seizures. The patient was initially treated for tuberculous meningitis after CSF findings showed lymphocytic predominance. However, lack of clinical improvement prompted further work up revealing a malignant process in the lumbosacral meninges. Dural biopsy showed atypical mononuclear infiltrates consistent with a B-cell non-Hodgkin lymphoma with immunohistochemistry showing CD20 positive, CD79a positive, CD3 negative. Being MUM1 positive and BCL2 positive suggests it being a diffuse large B cell lymphoma. A primary malignancy of the leptomeninges was ruled in after PET CT showed no other sites of high metabolic activity. The patient was able to complete 6 cycles of high dose Methotrexate and three Rituximab doses. Remarkably, after more than two years after his initial presentation, he still has mild signs of dementia but is able to carry out most activities of daily living with minimal assistance. The patient has survived beyond the expected life expectancy for PLL.

Primary Leptomeningeal Lymphoma: A Rare Mimicker of Idiopathic Intracranial Hypertension

“…3 Because of its wide range of presentations, PLML is commonly misdiagnosed as stroke, meningitis, polyradiculopathies, and rarely idiopathic intracranial hypertension (IIH). 5 Our patient was an obese woman who presented with headache, nausea, transient visual obscurations, and papilledema, which suggested IIH. 6 Symptoms and signs of IIH, if present, may only reflect those of generalized elevated intracranial pressure.…”

“…13 Our case was unique since previous cases reported papilledema and intracranial hypertension in men, 8,9,11 had significant associated neurological symptoms such as obtundation, 10 significantly compromised visual function, 12 or the main location of disease was in the spine. 9 Patients may present with only blurred vision without headache 5 and initial MRI brain may be normal. 6 The importance of CSF studies in cases atypical for IIH including male patients was emphasized by a case where a 49-year-old man with 6 weeks of headaches and transient visual obscurations with a normal MRI brain underwent transverse sinus stenting without LP.…”