High concentrations exist in nerve cells, neuroendocrine cells, and  tumor cells caused by these cells: 

1. Bronchial cancer:

 NSE is considered the preferred biomarker for  detecting small cell bronchial cancer, with 60% -81% of cases showing  elevated NSE concentrations. The concentration of NSE briefly  increases 24-72 hours after the start of the first chemotherapy cycle,  and can last for one week or rapidly decrease at the end of the first  chemotherapy cycle (with an increase in pre-treatment concentration). On the contrary, patients who do not respond to chemotherapy  will have a sustained increase or no decrease in NSE concentration  within the reference range. During the period of remission, 80-96% of  patients have normal NSE concentration, while NSE concentration  increases when the condition recurs. NSE can be used to evaluate the  prognosis, treatment effectiveness, and related etiology of small cell  lung cancer patients: diagnostic sensitivity of 93%, positive predictive  value of 92%. 

2. Neuroblastoma:

 Neuroblastoma is a common solid tumor in  children, originating from the spinal cord and often difficult to  diagnose accurately. 

3. Other tumors:

 In clinical practice, 68% -73% of patients with  seminomas have significantly increased NSE concentrations, which  are practically correlated with the clinical disease process. 22% of non  malignant lung diseases (regardless of tumor stage) have NSE concentrations higher than 25ng/mL. Patients with brain tumors such as  gliomas, spinal cord tumors, neurofibromas, and neuromas may  occasionally have elevated levels of NSE. 

4. Benign diseases: 

Patients with benign lung and brain diseases may  also have elevated serum NSE concentrations (>12ng/mL), such as  diffuse encephalitis, spinal cord and cerebellar degeneration, cerebral  ischemia, cerebral infarction, intracranial blood clots, traumatic brain  injury, schizophrenia, etc.