Thalamic Lymphoma

• Favorable Response to Conventional Chemoradiotherapy in Radiation-induced Glioma Harboring Coamplification of PDGFRA, KIT, and KDR: A Case Report and Literature Review
• Meta-analysis of altered gray matter volume in acute lymphoblastic leukemia patients' postchemotherapy via the AES-SDM
• Assessing the Effect of Cytoreduction on Solitary, Resectable Lesions in Primary Central Nervous System Lymphoma
• Primary large B-cell lymphoma of the central nervous system misdiagnosed as autoimmune encephalitis: a case report
• Free-hand Frameless Pinless Electromagnetic-Navigation (AXIEM™)-Guided Brain Lesion Biopsies: An Institution Based Experience from a Low-Middle-Income Country
• Neuroimaging insights into poor prognosis paraneoplastic encephalomyelitis: A case report on a challenging diagnosis revealed by MR imaging in a patient with Hodgkin's lymphoma
• Stereotactic biopsy for brain lesions: Doing more with less
• A Study of Clinical Profile, Radiological and Electroencephalographic Characteristics of Sporadic Creutzfeldt-Jakob Disease From a Tertiary Care Hospital

Thalamic Lymphoma is a rare form of primary central nervous system lymphoma (PCNSL) that affects the thalamus, a deep-seated brain structure crucial for sensory processing, motor control, and consciousness. PCNSL is typically a non-Hodgkin's lymphoma, most commonly of the diffuse large B-cell lymphoma (DLBCL) subtype.

### Clinical Features - Symptoms depend on the affected thalamic region but often include:

1. Cognitive decline (confusion, memory issues)
2. Altered consciousness (somnolence, coma in severe cases)
3. Hemiparesis or hemiplegia
4. Sensory deficits (contralateral hypoesthesia)
5. Ataxia or movement disorders (due to basal ganglia/thalamic involvement)
6. Seizures (though less common)
7. Increased intracranial pressure (headache, nausea, vomiting, papilledema)

### Imaging Findings - MRI with contrast:

1. Homogeneous enhancement on T1-weighted post-contrast images
2. Iso- to hypointense on T2/FLAIR
3. Restricted diffusion on DWI
4. Minimal perilesional edema (less than gliomas)
5. No necrosis or hemorrhage (unlike glioblastoma)

- PET scan:

1. Hypermetabolic lesion (high FDG uptake)

### Differential Diagnosis - Glioblastoma multiforme (GBM)

1. More heterogenous enhancement, necrosis, ring-enhancing lesions

- Thalamic infarct

1. No contrast enhancement, stroke history

- Demyelinating disease (e.g., multiple sclerosis, ADEM)

1. Multifocal, periventricular distribution

- Infectious causes (toxoplasmosis, TB, fungal abscess)

1. Immunosuppressed patients, multifocal ring-enhancing lesions

### Diagnosis - Stereotactic biopsy is crucial to confirm the diagnosis, as imaging alone is not definitive.

### Treatment - High-dose methotrexate (HD-MTX)-based chemotherapy

1. Often combined with rituximab and temozolomide/procarbazine

- Whole-brain radiation therapy (WBRT) (for refractory or recurrent disease) - Corticosteroids (can reduce tumor size but may obscure biopsy results) - Autologous stem cell transplantation (in select cases)

### Prognosis - Median survival: 2-5 years with optimal therapy - Poor prognosis factors:

1. Age >60 years
2. Poor performance status
3. Lack of complete remission after initial therapy