A paraneoplastic syndrome (PNS) is a complex condition that worsens the quality of life of patients. It presents diverse clinical manifestations and can be challenging to diagnose. The role of the SOX1 antibody in PNS has been gaining attention, but clinicians frequently lack an understanding of PNS cases with positive antibody results and complex symptoms. This lack of understanding can lead to misdiagnosis and missed diagnoses. In this report, we present a typical case to highlight the importance of considering PNS when patients present with cerebellar lesions, symptoms resembling Lambert-Eaton myasthenic syndrome (LEMS), signs of peripheral nerve injury, or subclinical evidence. Recognizing these indicators of PNS is crucial for improving early diagnosis and patient prognosis. By sharing this case, our goal is to increase awareness of these unique PNS cases and provide insight for diagnosis and treatment.