Microscopic examination shows that interlobular septa are thickened and infiltrated with plasma cells in large number. Leucocytes in the center of much dilated lymphatics have undergone necrosis and have lost their nuclear stain. About the periphery of the lumen and evidently derived from the swollen endothelial cells which surround it, are numerous large mononuclear cells. They act as phagocytes and ingest polynuclear leucocytes. Multinucleated giant cells, derived from these cells, occur. In several places thrombosed lymphatics in process of organization occur; the lumen is filled with compact fibrin which is invaded by fibroblasts and newly formed capillaries.
The process just described is analogous to that which occurs whenever an unopened abscess heals; mononuclear cells accumulate and act as phagocytes ingesting polynuclear leucocytes.
The following instance of streptococcus empyema is noteworthy because no suppurative pneumonia has been found in association with it. Nevertheless the character of the changes present in the lung indicate that the organ has been the site of an interlobular inflammation which has healed.
Autopsy 499.—J. H. M., white, aged twenty-four, a farmer from Arkansas, had been in military service five months. Onset of illness began two weeks before his admission to the hospital on November 15 with cough, fever, headache and malaise; on admission there was acute bronchitis. Thirteen days after admission the patient developed parotitis (mumps?); five days later and five days before death pleurisy was recognized on the right side and pneumonia was suspected. Death occurred thirty-six days after onset. The temperature on admission was 103.2° F. and remained elevated during one week falling by lysis; from this time until the pleurisy was recognized it was normal and later it remained approximately 103° F.
Anatomic Diagnosis.—Fibrinopurulent pleurisy on right side; fibrinous pleurisy on left side; fibrinopurulent pericarditis; chronic interstitial (interlobular) pneumonia in process of healing; purulent bronchitis; acute splenic tumor; parenchymatous degeneration of kidneys.
The right pleural cavity contains 1,650 c.c. of grayish yellow fluid containing an abundant sediment of softened fibrin. Part of this fluid, more opaque than the remainder is confined in a localized pocket between the inner surface of the lung and the pericardium. The apex and anterior surface of the right upper lobe, over an area about 7 cm. across, is held by fibrinous adhesions to the chest wall; when this adhesion is broken a pocket is exposed 6.5 x 2.5 cm. containing fibrin and fluid. The pericardial cavity is distended by 350 c.c. of turbid yellow seropurulent fluid. The pericardial surfaces are covered by shaggy, tough gray fibrin.
The right lung is collapsed; the lower and posterior part of the upper lobe is deep red and atelectatic. Throughout the upper lobe the interlobular septa are thickened, often 1 mm. across and very conspicuous; in the lower and anterior tip of the lobe is an area where tissue is firm grayish red and heavier than water. The lower and posterior half of the right lower lobe is firm and airless, and the tissue is reddish gray or gray and in places finely granular on section; interlobular septa are conspicuous. Although the lung is cut into thin sections, no abscesses are found. Bronchi throughout the lung contain mucopurulent fluid.
The left lung over its lower half is covered by a thin layer of fibrin. The tissue is crepitant throughout and moderately edematous. Bronchi contain mucopurulent fluid.
Hemolytic streptococci in pure culture are obtained from the blood of the heart, right pleural cavity and pericardium. No growth is obtained on a plate inoculated with material from the right lower lobe. The right bronchus contains hemolytic streptococci and B. influenzæ.
The pleural surface of the right lung is covered by a thick layer of fibrin which has undergone advanced organization. Fibrous septa within the lung are much thickened by the presence of newly formed fibrous tissue; the interstices of the tissue are distended and contain fibrin into which fibroblasts and new blood vessels have penetrated. Some lymphatics are plugged with fibrin and contain polynuclear leucocytes, lymphoid and large mononuclear cells. In several places organization of these thrombi is beginning. About the blood vessels are thrombosed lymphatics in which polynuclear leucocytes and mononuclear cells are equally abundant. Alveoli immediately adjacent to blood vessels and to fibrous septa often contain fibrin, and alveoli elsewhere contain desquamated cells in abundance.