NCIt definition : Interstitial pneumonia characterized by the presence of fibrosis in the interstitial
lung tissue. The pathologic diagnosis is based on the identification of fibrotic lesions
at different stages of development within a lung biopsy specimen. Typically there
are foci of normal lung parenchyma alternating with interstitial inflammation and
honeycombing. The term usual interstitial pneumonia sometimes is used interchangeably
with idiopathic interstitial fibrosis. The two terms are not entirely synonymous.
Usual interstitial pneumonia may be associated with other conditions such as connective
tissue disorders and asbestosis. The diagnosis of idiopathic interstitial fibrosis
requires the exclusion of such conditions. Patients with usual interstitial pneumonia
present with progressive dyspnea, cough, and restrictive pulmonary function abnormalities.
The prognosis is usually poor.;