The Neuron-specific Enolase Blood Test, or NSE Blood Test, is useful in the diagnosis and ongoing monitoring of patients with small cell lung carcinoma (SCLC). It may also be used in the diagnosis of other neuroendocrine tumors such as carcinoids, islet cell tumors and neuroblastomas. The test measures the level of neuron-specific enolase (NSE) in the blood serum.

The NSE Blood Test is most commonly used as a follow-up marker for patients with tumors that secrete NSE. Following successful treatment, NSE levels should fall. Consistent or rising levels, in the absence of another condition that could cause increased NSE levels, suggest a persistent tumor or tumor spread/recurrence. Other conditions that could cause elevated levels of NSE include epileptic seizure, encephalitis, brain injury, stroke, and rapidly progressive dementia.