Clinical Information

A spectrum of paraneoplastic neurologic disorders is associated with antineuronal nuclear antibody type1 (ANNA-1), also known as anti-Hu. ANNA-1 autoimmunity often manifests with multifocal neurological presentations. Typical presentations include neuropathies (mixed sensorimotor, sensory neuronopathy, autonomic neuropathy including gastrointestinal dysmotility/pseudo-obstruction or others), limbic encephalitis, cerebellar ataxia, encephalomyelitis, and myelopathy.

Small-cell lung carcinoma (SCLC) or other neuroendocrine tumors are almost always present in older adults, often as limited-stage disease. Extrapulmonary primary small-cell carcinoma, such as tumors of the skin, larynx, tongue, breast, cervix, prostate, endocrine, or pancreas, should be considered, especially in patients who do not smoke. Autopsy sometimes reveals SCLC in patients who lack evidence of tumor in life. In pediatric populations, neuroblastoma is sometimes encountered as the pertinent neoplasm. Other malignancies have also rarely been reported; in 15% of patients with confirmed SCLC, an unrelated and more apparent primary malignancy coexists with SCLC.