[Three Cases of Small-Cell Lung Cancer with Anti-Hu Antibody-Positive Paraneoplastic Neurological Syndrome].

This case series discusses 3 male patients in their 60s who presented with a chief complaint of sensory disorder in the upper or lower limbs. The patients were diagnosed with small-cell lung cancer(SCLC)with anti-Hu antibody-positive paraneoplastic neurological syndrome(PNS). Chest radiography at the initial visit revealed abnormalities in only one of the 3 cases. To confirm the diagnosis, a bronchoscopy was performed. However, the diagnosis could be confirmed in only 1 patient. In the other 2 patients, a diagnosis could not be made due to the small size of the primary lung tumor. The diagnosis was confirmed in the other 2 cases using endobronchial ultrasound-guided transbronchial needle aspiration at another hospital. Chemoradiotherapy led to tumor reduction in 2 patients. However, in all patients, the neurological symptoms could not be resolved with steroids, immunoglobulin, or anti-tumor treatment. For neurological disorders due to possible PNS, the anti-Hu antibody test, chest computed tomography, and ultrasonic bronchoscopy should be performed to ensure early diagnosis and treatment of SCLC.