Update in pulmonary carcinoid tumors: a review article

The diagnosis and medical management of advanced neuroendocrine tumors

Neuroendocrine tumors (NETs) constitute a heterogeneous group of neoplasms that originate from endocrine glands such as the pituitary, the parathyroids, and the (neuroendocrine) adrenal, as well as endocrine islets within glandular tissue (thyroid or pancreatic) and cells dispersed between exocrine cells, such as endocrine cells of the digestive (gastroenteropancreatic) and respiratory tracts. Conventionally, NETs may present with a wide variety of functional or nonfunctional endocrine syndromes and may be familial and have other associated tumors. Assessment of specific or general tumor markers offers high sensitivity in establishing the diagnosis and can also have prognostic significance. Imaging modalities include endoscopic ultrasonography, computed tomography and magnetic resonance imaging, and particularly, scintigraphy with somatostatin analogs and metaiodobenzylguanidine. Successful treatment of disseminated NETs requires a multimodal approach; radical tumor surgery may be curative but is rarely possible. Well-differentiated and slow-growing gastroenteropancreatic tumors should be treated with somatostatin analogs or alpha-interferon, with chemotherapy being reserved for poorly differentiated and progressive tumors. Therapy with radionuclides may be used for tumors exhibiting uptake to a diagnostic scan, either after surgery to eradicate microscopic residual disease or later if conventional treatment or biotherapy fails. Maintenance of the quality of life should be a priority, particularly because patients with disseminated disease may experience prolonged survival.

Treatment of carcinoid of the lung

PURPOSE OF REVIEW

Pulmonary carcinoids are rare neuroendocrine malignancies that comprise 2% of primary lung tumors. During the last few years, important information has appeared in the literature in relation to the histopathology, molecular biology, biologic behavior, and treatment of these tumors.

RECENT FINDINGS

Histologic subclassification of carcinoid tumors into atypical and typical is of paramount importance. Genetic changes in these subclasses are now well-known and are helpful for the differentiation. The biologic behavior of typical and atypical carcinoids is completely different, and treatment planning is based on this information. Surgery is the treatment of choice for localized carcinoid tumors and includes lymphadenectomy. In metastatic disease, chemotherapy with a cisplatin-based or streptozotocin-based combination is moderately effective. Palliation with biotherapy including interferon, somatostatin analogs, and octreotide is encouraging. Liver embolization is an option for symptomatic liver involvement.

SUMMARY

Pulmonary carcinoids are rare tumors, and our understanding of their histopathology and biologic behavior are the most important factors for treatment planning. Surgery is the treatment of choice for cure.