Pulmonary Carcinoid Tumours

Carcinoid tumours are neuroendocrine tumours derived from enterochromaffin cells, which are widely distributed in the body. Pulmonary carcinoids account for 25% of all carcinoid tumours and they comprise 1-2% of all lung tumours. The incidence of carcinoid tumours seems to be sharply increasing.Carcinoid tumours can be classified as typical or atypical, ranging from low-grade malignant to high-grade malignant, according to histological characteristics and differentiation level. Carcinoids can be placed in a spectrum of neuroendocrine tumours, ranging from low-grade malignant typical carcinoid to intermediate atypical carcinoid, to highgrade large cell neuroendocrine carcinoma and small cell lung carcinoma.Carcinoid pulmonary tumours can present with lymph node or distant metastases, most frequently at the liver. Carcinoid tumours have the ability to secrete many vasoactive peptides, most frequently serotonin. The hormonal secretion is related to systemic manifestations of carcinoid syndrome and carcinoid heart disease. Combining new diagnostic and treatment modalities in metastatic carcinoid patients may result in better prognosis. The review aims to elucidate the reader on the many aspects of carcinoid pulmonary tumours.