Vibroacoustic Disease and Respiratory Pathology IV –Lung and Pleura in a Lung Cancer Patient

摘要

BACKGROUND. Low frequency noise (LFN) (≤500 Hz, including infrasound) is aknown genotoxic agent. To date, 10 vibroacoustic disease (VAD) patients, have developed squamouscell carcinomas in the respiratory tract. In this report, fragments of lung and pleura of a VAD-lungcancer patient are studied through light and electron microscopy. METHODS. The patient was aretired, 62-year-old male Caucasian, smoker, and employed as an aircraft technician for over 30 years.With the patient’s informed consent, fragments of lung and pleura were removed during lungcarcinoma surgery. Specimens were prepared for light microscopy and transmission electronmicroscopy (TEM). RESULTS. Thickened vessel walls were identified. Numerous macrophages wereseen in the bronchioli and remaining lung parenchyma, some with brown pigment, and others with tar.TEM disclosed a marked reduction of type-I- pneumocytes, and a large increase of type-IIpneumocytes.Interstitial fibrosis was not uniformly distributed, but in some fields it was veryprominent. Cells under apoptotic processes were very common. The most remarkable feature seen inthe pleura was the increased thickness due to the intense collagen proliferation. DISCUSSION. Theincreased amount of focal fibrosis and of pleura and vessel wall thickening is an expected situationsince the same has already been observed in LFN-exposed rodents. The reduction of type-Ipneumocytesand an increase in type-II-pneumocytes is also seen in other pulmonary stress situations.The very frequent images of apoptotic processes in the remaining parenchyma lung tissue wereunexpected, and indicate possible avenues of research in the future.