Bronchial carcinoid tumors: clinical and radiological correlation.

Abstract To evaluate the incidence of bronchial carcinoid tumor (BCT) in population affected by various lung tumors, retrospectively reviewed between 1986-2001, and to emphasize the radiographic patterns if they are characteristic. In the above mentioned period, chest x-ray and CT were performed in 1110 patients, both male and female, affected by lung neoplasms. 20 patients were affected by BCT (16 males, and 13 females), aged between 26 and 75 years (mean age 57.5), with histopathologic diagnosis of typical (9 cases, 31%) and atypical (20 cases, 69%) bronchial carcinoid tumors. Localized right lung lesion were as follows: 7 cases in superior, 9 in middle and 4 in inferior lobes; in the left lung, 5 cases in superior, and 4 in inferior lobes. Size of the lesions was as average 2.4 cm in diameter (with a range of 0.5-12 cm). On x-ray and CT images, BCT appeared as a well marginated nodule, of which 9 were peripheral and 20 central. BCT are classified as neuroendocrine carcinomas,and are divided in typical and atypical forms, with variable grade of malignancy. Central neoplasms are symptomatic due to bronchial obstruction (i.e., pneumonia, atelectasis, bronchiectasis, emphysema and/or lung abscess); if airway obstruction is partial, then cough, wheezing and recurrent pulmonary infections occur. Peripheral tumors are generally asymptomatic and they are discovered occasionally, when chest x-ray is made for other reasons. Radiographic features are similar in typical and atypical BCT. In central tumors a rounded well circumscribed hilar mass is noted, with lobulated or bumpy margins. Central cavitation is not referred to. Peripheral BCT appear as a solitary nodule, inferioer then 3 cm in size, marginated, surrounded by normal pulmonary tissue. Signs and symptoms of BCT are evasive and vague. No current clinical or laboratory procedures are useful in confirming the diagnosis; particularly, no imaging modalities are able to differentiate between BCT and other pulmonary tumors. For this reason, a clinical radiologic endoscopic and histopathologic approach is necessary. CT is more sensiticve then conventional radiography, especially in detecting small lesions, calcification and enlarged lymph nodes. MRI may be useful in those patients, who cannot tolerate IV contrast media. Scintigraphy may be employed in discovering relapses and long standing metastases.