Bilateral pleural plaques and pulmonary fibrosis involving bases is hallmark of
**Core Concept**
Asbestosis is a lung disease caused by the inhalation of asbestos fibers, leading to chronic inflammation and fibrosis in the lung parenchyma. The condition is characterized by the presence of bilateral pleural plaques and pulmonary fibrosis, particularly affecting the lung bases.
**Why the Correct Answer is Right**
The hallmark features of asbestosis are bilateral pleural plaques and pulmonary fibrosis, which occur due to the chronic inflammation and scarring caused by asbestos fibers in the lung parenchyma. The lung bases are more affected due to the weight-bearing nature of the lungs and the gravitational distribution of asbestos fibers. The fibrosis in asbestosis is characterized by the formation of dense, collagenous scars that disrupt alveolar architecture and impair gas exchange.
**Why Each Wrong Option is Incorrect**
**Option A:** Asbestosis is not associated with hilar lymphadenopathy, which is more commonly seen in sarcoidosis. Asbestosis primarily affects the lung parenchyma, whereas sarcoidosis affects the lymph nodes and other organs.
**Option B:** Pulmonary embolism is not associated with bilateral pleural plaques, which are a hallmark of asbestosis. Pulmonary embolism typically presents with acute onset of dyspnea, chest pain, and tachycardia.
**Option C:** Idiopathic pulmonary fibrosis (IPF) is a distinct entity characterized by a more uniform pattern of fibrosis and the absence of pleural plaques. IPF is also more commonly associated with a worse prognosis than asbestosis.
**Clinical Pearl / High-Yield Fact**
Asbestosis is a preventable occupational lung disease, and its diagnosis is often delayed due to the long latency period between asbestos exposure and symptom onset. A thorough occupational history is essential in the diagnosis of asbestosis.
**Correct Answer:** C. Idiopathic pulmonary fibrosis (IPF) is a distinct entity characterized by a more uniform pattern of fibrosis and the absence of pleural plaques. IPF is also more commonly associated with a worse prognosis than asbestosis.