Paraneoplastic neurological syndrome with positive anti-Hu and anti-Yo antibodies: A case report

Abstract

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.

CASE SUMMARY

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.

CONCLUSION

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.

Keywords: Paraneoplastic syndrome; Anti-Hu antibody; Anti-Yo antibody; Small cell lung cancer; Breast cancer; Intravenous immunoglobulin; Case report

Core Tip: Neurological paraneoplastic syndrome is a common manifestation in patients with tumors, and in some cases, it appears earlier than the tumor. We report a rare case in which two different paraneoplastic antibodies were present. While most previous studies have reported this syndrome due to one tumor, this patient presented with two different tumors and two paraneoplastic antibodies at the same time, causing neurological symptoms such as ataxia, limb numbness, and weakness. This case highlights the specificity of paraneoplastic antibodies to their corresponding tumors, avoiding a missed diagnosis when multiple antibodies are present and providing a reference for future clinical diagnosis.