UNASSIGNED: Paraneoplastic peripheral neuropathy (PPN) caused by olfactory neuroblastoma (ONB) has not yet been reported.
UNASSIGNED: We present a rare case of an adult who hospitalized repeatedly over the past 9 months for persistent pain and numbness in the limbs. This patient was initially diagnosed with chronic inflammatory demyelinating polyneuropathy (CIDP) and treated accordingly, but neurological symptoms did not improve significantly. After this admission, FDG-PET/CT showed focal hypermetabolism of a soft-tissue mass in the nasal cavity, and further lesion biopsy suggested ONB. Combined with positive serum anti-Hu antibody, the diagnosis of PPN associated with ONB was eventually made. Furthermore, the patient\'s neurological symptoms were relieved after removal of the primary tumor, confirming the accuracy of the diagnosis.
UNASSIGNED: Our case not only expanded the clinical characteristics of ONB but also highlighted the importance of early and comprehensive tumor screening for the diagnosis of PPN.

BACKGROUND: Paraneoplastic neurological syndrome (PNS) is a rare complication in patients with cancer. PNS can affect the central, peripheral, autonomic nervous system, neuromuscular junction, or muscles and cause various neurological symptoms. Anti-Yo antibody-positive neurological paraneoplasms and anti-Hu antibody-positive neurological paraneoplasms are common, but coexistence of both types has not been described in the literature.
METHODS: Here we present a rare case of paraneoplastic neuropathy occurring in both breast and lung cancers. A 55-year-old woman was admitted to our hospital with unsteadiness while walking. The patient had a history of breast cancer two years previously. Chest computed tomography revealed a 4.6 cm × 3.6 cm mass in the right lung, which was diagnosed as small-cell lung cancer (SCLC). Blood test was positive for anti-Yo antibodies, and the cerebrospinal fluid was positive for both anti-Yo and anti-Hu antibodies, and the neurological symptoms were considered to be related to the paraneoplasm. The patient was treated with a course of intravenous immunoglobulin, without noticeable improvement. After being discharged from hospital, the patient underwent regular chemotherapy for SCLC and periodic reviews. The patient\'s neurological symptoms continued to deteriorate at the follow-up visit in April 2021.
CONCLUSIONS: This case suggests the possibility of two types of tumors appearing simultaneously with two paraneoplastic antibodies. The clinical appearance of two or more paraneoplastic tumors requires additional attention.

Autoimmune epilepsy (AE) refers to epilepsy mediated by autoantibodies or immune cells, and a large proportion of drug-resistant epilepsy cases are classified as AE. AE lacks standardized management guidelines. At present, little research has been conducted on the effectiveness of surgical treatment of AE. This paper reports a patient whose surgical treatment was ineffective before AE was diagnosed and who improved after immunotherapy. A literature review was conducted to examine the progress of surgical treatment of epilepsy, the relationship of temporal lobe epilepsy to neuronal antibodies, surgical and prognostic factors, research progress on the anti-Hu antibody, and treatment of autoimmune encephalitis to provide a clinical reference.

We report a woman with unilateral Adie\'s pupil associated with peripheral sensorimotor polyneuropathy, elevated anti-Hu antibody, and primary mediastinal small cell carcinoma (SCC). To our knowledge, this is the first report of Adie\'s pupil in a patient with mediastinal SCC. Although rare, Adie\'s pupil and sensorimotor polyneuropathy may be the first manifestation of cancer. Its rapid recognition facilitates an early diagnosis and treatment.