Anti-Yo Positive Paraneoplastic Cerebellar Degeneration Following Endometrial Cancer Treatment

Case at a Glance

A 78-year-old female with recently treated endometrial cancer developed severe neurological symptoms consistent with paraneoplastic cerebellar degeneration, testing positive for anti-Yo antibodies. Despite successful cancer treatment, she experienced significant functional decline with ataxia, dysphagia, and tremor.

Patient's Story

The patient is a 78-year-old woman with a medical history significant for hyperthyroidism (on methimazole), hypertension (on valsartan), hyperlipidemia (on atorvastatin), asthma (on Dulera), and anticoagulation therapy (on Eliquis). She was diagnosed with endometrial cancer in October 2024, which had metastasized to the lungs. She underwent hysterectomy in March 2025 and received five cycles of carboplatin and paclitaxel chemotherapy, with pembrolizumab added to the final cycle. The oncological treatment was successful, achieving complete remission with no evidence of residual cancer.

Initial Assessment

In late December 2024 to early January 2025, the patient began experiencing progressive neurological symptoms including severe gait ataxia requiring wheelchair use, urinary retention necessitating Foley catheter placement, dysphagia, and intermittent right-hand tremor. She became functionally dependent and required comprehensive supportive care. Depression was identified as a contributing factor to her clinical decline.

The Diagnostic Journey

Following the onset of neurological symptoms, the patient was evaluated by neurology and subsequently referred to neuro-oncology for specialized assessment. Laboratory testing revealed positive anti-Yo antibodies, confirming the diagnosis of paraneoplastic cerebellar degeneration. Despite the neurological decline, imaging studies confirmed sustained cancer remission with no evidence of recurrent malignancy.

Final Diagnosis

Anti-Yo positive paraneoplastic cerebellar degeneration secondary to treated endometrial carcinoma, with associated major depressive disorder.

Treatment Plan

The neuro-oncology team discussed plasmapheresis as a potential therapeutic intervention but ultimately recommended against it due to unfavorable risk-benefit ratio given the patient's age and functional status. Instead, the focus shifted to supportive care with enrollment in palliative care services. The patient was started on antidepressant therapy and engaged in multidisciplinary rehabilitation including physical therapy, occupational therapy, and speech therapy. Hospice care was discussed as a future option given the generally poor prognosis associated with anti-Yo positive paraneoplastic syndromes.

Outcome and Follow-up

The patient showed modest improvements in mood and function following initiation of antidepressant therapy and increased social support. She demonstrated some progress in rehabilitation therapies and improved oral intake. The family elected to continue supportive care and rehabilitation while maintaining palliative care involvement. Long-term prognosis remains guarded given the typical irreversible nature of anti-Yo associated neurological damage, though individual outcomes can vary.