# A case of Anti-Hu and Anti-Zic4 paraneoplastic cerebellar degeneration in a patient with stage IV adenocarcinoma of Müllerian origin

## TL;DR

A rare case of neurological degeneration caused by antibodies in a patient with advanced gynecologic cancer is reported, emphasizing the need for better diagnosis and treatment.

## Contribution

This is the first reported case of Anti-Hu and Anti-Zic4 paraneoplastic cerebellar degeneration associated with Müllerian origin adenocarcinoma.

## Key findings

- Anti-Hu and anti-Zic4 antibodies were detected in cerebrospinal fluid of a patient with stage IV Müllerian origin adenocarcinoma.
- Despite treatment with corticosteroids and plasmapheresis, the patient showed minimal neurological improvement.
- The case underscores the rarity and poor outcomes of Anti-Hu-associated PCD in gynecologic malignancies.

## Abstract

•Paraneoplastic cerebellar degeneration (PCD) presents as progressive cerebellar dysfunction.•Diagnosis of PCD includes physical examination, imaging, cerebrospinal fluid analysis, and testing for onconeural antibodies.•Several onconeural antibodies are associated with PCD, including anti-Yo, anti-Tr, anti-Ri, and anti-Hu.•Treatment modalities include primary tumor resection, corticosteroids, IVIG, and plasmapheresis.•PCD should be considered in patients with known malignancy when neurologic symptoms arise.

Paraneoplastic cerebellar degeneration (PCD) presents as progressive cerebellar dysfunction.

Diagnosis of PCD includes physical examination, imaging, cerebrospinal fluid analysis, and testing for onconeural antibodies.

Several onconeural antibodies are associated with PCD, including anti-Yo, anti-Tr, anti-Ri, and anti-Hu.

Treatment modalities include primary tumor resection, corticosteroids, IVIG, and plasmapheresis.

PCD should be considered in patients with known malignancy when neurologic symptoms arise.

Paraneoplastic cerebellar degeneration (PCD) is a rare neurological complication of malignancies, resulting from autoimmune responses targeting antigens shared by neurons and tumors. It is characterized by progressive cerebellar dysfunction, including ataxia and dysarthria, and is associated with anti-onconeuronal antibodies such as Anti-Yo and Anti-Hu. While most cases of Anti-Hu-associated PCD occur in patients with small cell lung cancer, their association with gynecologic malignancies is exceedingly rare. This is the first reported case in the literature of a patient with adenocarcinoma of Müllerian origin complicated by Anti-Hu PCD.

We present the case of a 73-year-old female with stage IV adenocarcinoma of Müllerian origin who presented with worsening ataxia and dysarthria after undergoing outpatient chemoimmunotherapy to treat her gynecologic malignancy. CT and MRI Brain imaging revealed nonspecific findings, but cerebrospinal fluid (CSF) analysis revealed the presence of positive anti-Hu and anti-Zic4 antibodies, consistent with a diagnosis of PCD. Despite treatment with high-dose intravenous corticosteroids and plasmapheresis in the acute setting, the patient displayed minimal improvement and continued to experience persistent neurological impairment.

Despite advancements in diagnostic criteria and the availability of multiple types of therapies, outcomes for PCD remain poor. This is especially notable for cases associated with Anti-Hu antibodies. This case highlights the importance of considering PCD in the differential diagnosis of patients with malignancies and unexplained neurological symptoms. Furthermore, it highlights the critical need for continued research to refine diagnostic methods and develop more effective, evidence-based treatment strategies to improve outcomes.