A case report: primary central nervous system lymphoma misdiagnosed as neuromyelitis optica.

BACKGROUND: Primary central nervous system lymphoma (PCNSL) occurring in the spinal cord is very rare. Due to its atypical clinical symptoms and imaging manifestations, it is extremely easy to be misdiagnosed as other diseases. This study reports a case of PCNSL misdiagnosed as neuromyelitis optica (NMO) and analyses neuroimaging characteristics that may aid in the diagnostic evaluation of PCNSL. CASE REPORT: The case reports a 44-year-old man who presented with clinical symptoms including persistent neck pain, upper limb weakness, blurred vision in the left eye. His Aquaporin4 antibody (AQP4 antibody) was slightly positive (1:10), and cervical spinal cord magnetic resonance imaging (MRI) showed the continuous segment and multifocal areas throughout cervical spinal cord with obvious homogenous enhancement, leading to an initial misdiagnosis of NMO. His symptoms progressively improved after steroid pulse treatment, but worse after steroid tapering. Following magnetic resonance spectroscopy (MRS) and positron emission tomography (PET) examinations, PCNSL should be firstly considered. Immunohistochemical analysis confirmed this diagnosis. After undergoing chemotherapy, the patient’s lesion area was reduced. Unfortunately, the patient ultimately died after being hospitalized for 9 months. CONCLUSION: Since PCNSL, especially in the spinal cord, is uncommon, its neuroimaging appearance could be misdiagnosed with other conditions, such as NMO, when there is positive expression of AQP4 antibody. Special attention should be made to the clinical symptoms and follow-up brain and spinal MRI as well as histopathologic examination are recommended for early diagnosis and treatment.