High Serum Neuron-Specific Enolase (NSE) Level Firstly Ignored as Normal Reaction in a Small Cell Lung Cancer Patient: a Case Report and Literature Review

Background: High serum neuron-specific enolase (NSE) level has been in use as a tumor marker; however, some physicians may ignore NSE levels in serum, especially when the patients are asymptomatic. Here we report a case that a 51 year old female patient with no respiratory symptoms who had a NSE level which increased extremely over three months and was eventually diagnosed small cell lung cancer (SCLC). Methods: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) in right pulmonary hilar enlarged lymph node was performed for diagnosis. Results: EBUS showed right pulmonary hilar lymph node enlargement. A TBNA biopsy histopathology diagnosed SCLC. Conclusions: We should pay attention to high serum NSE levels, especially when the index increased extremely over a short time.