A 54-year-old woman with ovarian carcinoma develops progressive gait ataxia, dysarthria, and nystagmus over six weeks. MRI shows cerebellar atrophy, and CSF analysis reveals inflammatory changes. Serum antibodies are directed against a cytoplasmic antigen expressed by Purkinje cells. Which antibody is most consistent with this presentation?
- A Anti-VGCC
- B Anti-Hu (ANNA-1)
- C Anti-Yo (PCA-1) ✓
- D Anti-NMDA receptor
Correct answer: C. Anti-Yo (PCA-1)
Explanation
Paraneoplastic cerebellar degeneration with anti-Yo (Purkinje cell cytoplasmic antibody type 1) occurs predominantly with gynecologic cancers, especially ovarian, and breast carcinoma. Anti-Hu causes limbic encephalitis and sensory neuronopathy in small cell lung cancer, anti-VGCC causes Lambert-Eaton myasthenic syndrome, and anti-NMDA receptor encephalitis is associated with ovarian teratoma in young women presenting with psychiatric features and dysautonomia rather than pure cerebellar degeneration.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.