RESUMO
BACKGROUND: Primary non-dural central nervous system mucosa-associated lymphoid tissue (MALT) lymphoma is a rare indolent B-cell lymphoma, with only a few reported cases worldwide. CASE SUMMARY: A 33-year-old man presented with a 5-mo history of left blepharoptosis and a 4-mo history of right limb numbness and weakness. Magnetic resonance imaging showed a significantly enhanced mass in the left midbrain. Subsequent positron emission tomography revealed that the lesion had increased glucose uptake. A stereotactic robotic biopsy supported a diagnosis of MALT lymphoma. Then he was treated with radiation therapy (30Gy/15F), which resulted in complete remission. We also review the literature on brain parenchymal-based MALT lymphoma, including the clinical presentation, treatment options, and outcomes. CONCLUSION: Although there is no consensus on the optimal treatment for this rare disease, patients can respond well when treated with radiotherapy alone.