Interstitial hyperplasia of the lungs, a pathologic description of lung lesions. Lung tissue is made up of parenchyma and interstitium, and the structures in the interstitium are mainly blood vessels and lymphatic vessels. Simply put, interstitial hyperplasia is an over-repair of the structures in the interstitium, resulting in thickening of the interstitium.
The lungs are made up of alveoli and the structures that support them. To make an analogy, think of the lungs as a building, with the alveoli being the equivalent of each room and the interstitium being the equivalent of the walls, which contain blood vessels through which oxygen has to pass to enter the blood vessels before it can be transported throughout the body. Usually, interstitial hyperplasia occurs when the alveoli are damaged and the interstitium undergoes over-repair, leading to interstitial hyperplasia, which interferes with the exchange of oxygen.
There are many causes of interstitial hyperplasia, either infectious, such as viral pneumonia that can present with inflammation of the interstitium, or non-infectious, such as interstitial pneumonitis secondary to connective tissue disease and idiopathic pulmonary fibrosis.
Diagnosis of interstitial lung hyperplasia requires prompt medical attention to avoid delays.