RESUMO
In the bronchial epithelium, smoking initiates a multistep process that first appears histologically as premalignant squamous metaplasia/dysplasia, a biological predecessor of squamous-cell lung cancer. Reflecting chromosomal damage from a carcinogenic insult, micronuclei may reveal earlier events in the carcinogenic sequence. We prospectively evaluated and correlated micronucleus count, histology (index of metaplasia) and smoking exposure in 35 consecutive subjects (9 active smokers, 10 previous smokers and 16 never-smokers) undergoing diagnostic bronchoscopy. Samples for micronuclei and histological evaluation were taken from the main carinal mucosa in each subject for site-specific comparisons. The median and mean micronucleus counts per 1,000 cells were significantly higher in active smokers than in non-smokers (subjects who had never smoked and previous smokers): median counts were 3.7 vs. 1.4, p = 0.03; mean counts were 4.7 vs. 1.9, p = 0.01. There was no significant difference, however, in micronucleus counts between subjects who had never smoked and previous smokers. Bronchial metaplasia and smoking history were not associated. Our findings suggest that micronuclei are a readily quantitated, early intermediate-endpoint marker for detecting tobacco-initiated tracheobronchial carcinogenesis.
Assuntos
Brônquios/patologia , Neoplasias Pulmonares/patologia , Micronúcleos com Defeito Cromossômico/ultraestrutura , Neoplasias da Traqueia/patologia , Adulto , Idoso , Epitélio/patologia , Feminino , Humanos , Neoplasias Pulmonares/diagnóstico , Masculino , Pessoa de Meia-Idade , Mucosa/patologia , Estadiamento de Neoplasias , Fumar , Neoplasias da Traqueia/diagnósticoRESUMO
We reviewed 17 cases of biopsy-proven sarcoidosis occurring in patients who were 65 years of age or older at the time of diagnosis in order to determine the clinical features of sarcoidosis in this group of elderly patients. A female preponderance (76%) was noted, as well as significant respiratory and cutaneous symptoms. There were no characteristic diagnostic features of sarcoidosis in this group; therefore, we suggest that tissue biopsy is needed to exclude pulmonary diseases such as neoplasm or tuberculosis. Most elderly patients having sarcoidosis remained clinically stable during the period of follow-up and did not require therapy for sarcoidosis. We propose that sarcoidosis should be considered in the differential diagnosis of elderly patients presenting with pulmonary or multisystem disease.