Update in pulmonary carcinoid tumors: a review article

Pulmonary carcinoid tumors are neuroendocrine malignant tumors that make up 1% to 2% of all lung tumors. According to histopathologic criteria, carcinoids can be divided into typical (TC) and atypical (AC) carcinoids. Carcinoids can be placed in a spectrum of neuroendocrine tumors, ranging from low-grade malignant TC to intermediate AC to high-grade large-cell neuroendocrine carcinoma and small-cell lung carcinoma. Familial pulmonary carcinoids are rare. The most common symptoms are hemoptysis, cough, recurrent pulmonary infection, fever, chest discomfort and chest pain, unilateral wheezing, and shortness of breath. Paraneoplastic syndromes are rare and include carcinoid syndrome, Cushing's syndrome, and ectopic growth hormone-releasing hormone secretion. The diagnosis is usually established by flexible bronchoscopy and biopsy, although occasionally this can result in severe hemorrhage. Immunoscintigraphy by somatostatin analogs can also be useful in diagnosis. The treatment of choice is surgical resection, and prognosis is relatively good in TC, although it is worse in AC. The role of radiotherapy and chemotherapy as part of multimodality treatment or palliation is still debated.