[Heterogeneity of bronchial carcinoid tumors. Place of atypical forms].

Atypical carcinoid is an intermediate form between low grade malignant typical carcinoid and high grade malignant small cell carcinoma which are the two ends of the spectrum of neuroendocrine bronchopulmonary tumors. Between 1983 and 1993, twenty-three atypical carcinoids underwent surgical treatment. Histologic diagnosis of atypical carcinoid was established if the criteria proposed by Arrigoni et al, were fulfilled. Diagnosis was most frequently based on screening chest roentgenogram (56%). CT-scan findings showed a nodular peripheral mass in 65% of patients and central mass or atelectasis in 35% of patients. Four pneumonectomies, 15 lobectomies, 2 segmentectomies and 2 wedge resections were performed. Nine patients (39%) had regional nodal metastases and 4 patients (17%) had mediastinal nodal metastases (N2 disease) at the time of surgery. There were 4 death related to recurrence of the disease with distant metastasis in 3 patients (14%). Ten-year survival in atypical form was 59% contrasting with the 90% ten-year survival rate in patient with typical form operated on the same period. Because of their aggressive behavior, atypical carcinoids were comparable to well differentiated carcinoma of the lung and require an aggressive approach with lobectomy and mediastinal lymph node dissection being a minimum procedure.