Describe the gross appearance of this lung representative of the disease process in your patient's lungs. There is extensive granulomatous disease involving the lung parenchyma. Mainly upper lobe is involved. The larger tan-white granulomas have caseation with central necrosis and in some areas become almost confluent. Describe the microscopic appearance of the lungs.
Granulomatous inflammation is present.
The granulomas demonstrate central caseation and surrounding epithelioid macrophages. Some Langhans giant cells are seen. Also contributing to the inflammatory reaction are lymphocytes. The acid fast stain demonstrates many slender red rods consistent in morphology with Mycobacteria. A tuberculin skin test is used mainly for screening patients for possible tuberculosis.