Failure of resolution in pneumonia. 
An account is given of the clinical, radiological and pathological features of 50 cases of pneumonia in which resolution was incomplete.  This phenomenon occurs mainly in middle-aged and elderly men with chronic bronchitis and may simulate bronchial carcinoma.  It most frequently affects the right upper lobe.  Fibrosis and inflitration by chronic inflammatory cells are the characteristic histological abnormalities.  Serious long-term sequelae are uncommon.