Symptoms and diagnostics of lung neuroendocrine tumors

Pulmonary neuroendocrine tumors comprise 20% of all lung cancers. They are separated into 4 subgroups: typical carcinoid tumor, atypical carcinoid tumor, large-cell neuroendocrine carcinoma, and small-cell lung carcinoma. The major symptoms present in 60% of patients are cough, hemoptysis, and obstructive pneumonia. They may also exhibit hormonally related symptoms e.g. carcinoid syndrome. Small cell lung cancer is the most common subgroup, with rapid progression, aggressive metastatic potential and the worst prognosis. Large cell neuroendocrine carcinoma is rare but also has a poor prognosis. Typical carcinoid may be accompanied with hormone related symptoms and has the best prognosis; atypical one on the contrary may cause lymph node and distant metastases in half of the cases. Elevated plasma levels of chromogranin-A are present in majority of pulmonary neuroendocrine tumors and act as tumor marker. The mainstay of treatment is radical surgery if possible. In locally advanced or metastatic disease combination chemotherapy and somatostatin-analogues may have beneficial effect. This review focuses on the general features, and current diagnostic options of pulmonary neuroendocrine tumors.