Primary Central Nervous System Lymphoma: Recognizing the Key Symptoms and Neurological Impacts

Primary Central Nervous System Lymphoma (PCNSL) is a rare and aggressive form of non-Hodgkin lymphoma that originates in the brain, spinal cord, or eyes. Unlike systemic lymphomas, PCNSL remains confined to the central nervous system (CNS), making its presentation unique and often challenging to diagnose. Because tumors develop directly within critical neurological regions, symptoms vary significantly depending on the tumor's location and size.

Common Neurological Symptoms of PCNSL

One of the earliest and most frequently reported signs of PCNSL is persistent headache, often accompanied by dizziness and generalized weakness. A hallmark feature is unilateral limb weakness—meaning patients may experience reduced strength or motor control in either the left or right arm and leg. This focal neurological deficit can mimic conditions like stroke or multiple sclerosis, leading to potential misdiagnosis if imaging is not performed promptly.

Visual Disturbances Due to Optic Pathway Involvement

When lymphoma develops near or exerts pressure on the optic nerves or chiasm, patients may suffer from blurred vision, partial vision loss, or even double vision. These visual impairments are typically progressive and may affect one or both eyes. Early recognition of these ocular symptoms is crucial, as they can sometimes precede more severe neurological deterioration.

Motor and Cognitive Dysfunction Based on Tumor Location

Motor deficits occur when the tumor infiltrates areas of the brain responsible for movement, such as the motor cortex or basal ganglia. Depending on the affected region, individuals might struggle with coordination, exhibit muscle stiffness, or experience difficulty walking. In some cases, these symptoms are initially mistaken for Parkinson's disease or other neurodegenerative disorders.

Emotional and Behavioral Changes Linked to Frontal Lobe Involvement

If the lymphoma impacts brain regions associated with mood and behavior—particularly the frontal lobes—patients may undergo dramatic personality shifts. Someone who was previously emotionally stable might suddenly display erratic emotions, including unexplained outbursts of laughter or crying, apathy, or socially inappropriate actions. These psychiatric-like symptoms can be misleading, often resulting in referrals to mental health specialists before a neurological cause is considered.

Differential Diagnosis and Clinical Overlap

Because PCNSL presents with mass effect and inflammation, its clinical picture frequently overlaps with other intracranial pathologies such as brain hemorrhage, ischemic stroke, gliomas, or metastatic tumors. Imaging studies like MRI with contrast enhancement typically reveal well-defined, periventricular lesions that help differentiate PCNSL from other conditions. However, definitive diagnosis requires histopathological examination via biopsy.

In summary, Primary Central Nervous System Lymphoma manifests through a wide spectrum of neurological and psychological symptoms, heavily influenced by tumor location. Awareness of these diverse presentations—ranging from motor weakness and vision problems to emotional dysregulation—is essential for early detection and effective intervention. Given its rarity and symptom overlap with more common disorders, PCNSL should remain a consideration in any adult presenting with rapidly progressing neurological decline without an obvious cause.