Case Presentation:

A 56‐year‐old woman presented to the Emergency Center (EC) complaining of dizziness and lack of balance. Neurology diagnosed her with peripheral vertigo and sent her home. Over the next 2 months she developed progressive ataxia, followed by dysarthria and dysphagia. She presented to the EC again and neurology noted she had signs of cerebellar degeneration. An MRI showed no abnormalities. Neurology remained concerned for a paraneoplastic, infectious, toxic, or neurodegenerative process leading to the patient’s symptoms. Oncology was consulted and a paraneoplastic work‐up was sent. The patient went home at her request with a plan for outpatient follow up. She continued to decline, and therefore presented to the EC again. The medicine service was consulted for admission. At the time of my evaluation, the patient could no longer sit up unassisted. For 2 weeks she had experienced progressive nausea and vomiting and she felt dehydrated. On exam, she had akathisia, marked dysarthria, lateral nystagmus, dysmetria, and difficulty with rapid alternating movements. Review of the medical record revealed that the paraneoplastic work‐up had returned, and the anti‐Yo antibody was positive. I was concerned for an occult malignancy and consulted oncology, but they felt I should evaluate other potential etiologies for her symptoms. After literature review I remained concerned for malignancy of the breast, ovary, or uterus. Breast exam and a recent CT of the chest/abdomen/pelvis were unremarkable. I consulted gynecology for an evaluation. They performed a thorough exam, and an endometrial biopsy revealed papillary serous endometrial cancer. The patient underwent hysterectomy. Unfortunately she continued to do poorly and opted for hospice care.

Discussion:

Paraneoplastic Cerebellar Degeneration (PCD) is a rare condition, and diagnosis requires recognition of the clinical signs of cerebellar dysfunction along with testing for associated antibodies. Other conditions should be considered including brain metastases, infections, toxins, neurodegenerative conditions and nutritional deficiencies. MRI is frequently normal but helps rule out other pathology. The presence of Anti‐Yo antibodies in the setting of cerebellar degeneration serves as almost certain proof of a paraneoplastic syndrome, with underlying breast, ovarian, or endometrial cancer as the culprit. Our oncology consultants felt the absence of an evident cancer argued against a paraneoplastic syndrome. Neurologic symptoms in PCD occur prior to diagnosis of a cancer 60‐70% of the time, and can be rapidly progressive and devastating.

Conclusions:

PCD is rare and can be difficult to identify. Even specialists may not be well versed when it comes to obscure diseases, and as hospitalists we must read for ourselves and not completely rely on our consultants. Pursuing the diagnosis and treatment of the unseen cancer is the only known treatment for PCD. Sadly, prognosis for neurologic recovery is very poor.