Pulmonary artery aneurysm rupture

Abstract

Pulmonary artery aneurysm is a disorder of varying etiology and should be diagnosed early for appropriate interventions. A 45-year-old man was hospitalized for chest pain, dyspnea, cough, chills, diarrhea, and vomiting, which had started 3 weeks before admission. Physical examination indicated a reduced vesicular murmur in the right hemithorax. A chest x-ray performed indicated a pneumothorax and pulmonary abscess in the right hemithorax. Thoracostomy released abundant purulent and fetid fluid. Direct examination of the pleural fluid using saline revealed structures similar to Trichomonas. Non-contrast chest computed tomography revealed right pneumothorax along with an irregular cavitation located at the pleuropulmonary interface of the posterior margin of the right lower lobe. A pleurostomy was performed. On the second postoperative day, the patient suffered a sudden major hemorrhage through the surgical wound and died on the way to the operating room. The autopsy revealed an abscess and ruptured aneurysm of the lower lobar artery in the lower right lung. Microscopic examination revealed extensive liquefactive necrosis associated with purulent inflammation and the presence of filamentous fungi and spores. This case can be characterized as a severe disorder that requires early diagnosis to achieve a good therapeutic response and to avoid fatal outcomes.

Keywords: Aneurysm, Rupture; Hemoptysis; Lung abscess; Thoracotomy; Trichomonas Infections.

Figure 1. Direct examination of the pleural fluid showing structures similar to Trichomonas (red circles).

Figure 2. Chest x-ray in postero-anterior view showing the pneumothorax with an area suggestive of a lung abscess in the right lung.

Figure 3. Thoracic computed tomography revealing the right pneumothorax with irregular cavitation with thickened walls located at the pleuropulmonary interface of the posterior margin of the right lower lobe. A – Sagittal plane; B – axial plane.

Figure 4. Macroscopic examination of the right lung (posterior face) showing rupture of the lower lobar artery (white arrowhead) and the abscess surrounding the artery. The inset shows the PAA in detail.

Figure 5. Photomicrograph of the lung showing arterial wall rupture. (Masson's trichrome stain; 20X).

Figure 6. Photomicrographs of: A – Aneurysm wall showing purulent inflammatory infiltrate and coagulative necrosis (H&E, 200X); B – Pulmonary artery aneurysm wall with coagulative necrosis, intimal fibroplasia, and mixed inflammatory infiltrate (H&E, 100X); C – Pulmonary artery aneurysm wall with coagulative necrosis, intimal fibroplasia, and mixed inflammatory infiltrate (H&E, 100X); D – Granulation tissue and fibrinopurulent pseudomembrane on the inner surface of the pulmonary abscess contiguous to the pleural empyema (H&E, 200X).

Figure 7. A – Infiltration of filamentous fungi and spores (Grocott's methenamine silver stain, 40X); B – Numerous septet and branched hyphae and spores infiltrating connective tissue on the inner surface of the pleural cavity and pulmonary parenchyma exposed through pleurostomy (Grocott's methenamine silver stain, 400X).