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Mucoepidermoid tumors of the lung: analysis of 11 cases.

BACKGROUND
Mucoepidermoid tumors (METs) of the trachea and bronchi are rare. They derive from the minor salivary gland tissue of the proximal tracheobronchial tree, and their clinical behaviors are still controversial. Herein, we analyze 11 cases of MET to investigate its clinicopathological characteristics.


METHODS
The medical records and pathological examinations of patients diagnosed with MET from May, 1995 to May, 2001 at the Division of Thoracic Surgery in Taipei Veterans General Hospital were retrospectively reviewed.


RESULTS
There were 11 patients (7 male and 4 female) aged from 19 to 79 years, with a peak at the seventh and eighth decade. The mean age at diagnosis was 58.9 years, and 9 of these 11 patients were symptomatic. No surgical mortality occurred. Three patients with low-grade tumors were all young females (less than 30 years). They were all alive without evidence of disease recurrence until the date of analysis, whereas the 5-year survival of 8 patients with high-grade tumors was only 25%. Six patients with high-grade tumors received adjuvant therapy, but their prognoses remained poor.


CONCLUSIONS
In the current study, METs occurred more frequently in male patients. Young female patients were preponderant to have low-grade tumors and therefore associated with better prognosis. Histological grading of the MET and the ability to achieve an anatomic resection are 2 most important factors that affect prognosis. Adjuvant therapy seems not to be effective in patients with high-grade MET.