Granulomatous Pneumocystis carinii Pneumonia in Three Patients with the Acquired Immune Deficiency Syndrome: Case Reports
A transcutaneous needle biopsy of the nodule showed nonspecific fibrosis. Special stains for organisms were negative. A 5-TU tuberculin test was nonreactive. Several weeks later she was admitted to Mount Sinai Hospital. Her past medical history was remarkable for an upper GI bleed secondary to peptic ulcer disease several months earlier, a herpes zoster infection one year earlier, and a cigarette smoking history of one pack per day Physical examination revealed a temperature of 38.3°C, oral thrush, and clear lungs on auscultation. Her admission blood gas analysis values were pH, 7.44; PaC02, 38.7 mm Hg; and Pa02, 92 mm Hg on room air. A chest x-ray film again revealed a nodule, and a chest CT scan confirmed a 2 X 3-cm left suprahilar parenchymal mass and a smaller, ill-defined left lingular mass (Fig 1). other
An indium scan revealed no pulmonary uptake of the isotope. Pulmonary function tests disclosed a forced vital capacity of 4.77 L (111 percent predicted), and the carbon monoxide diffusing capacity was 20.27 ml/mm Hg (88 percent predicted). Transbronchial and transcutaneous biopsies were again nondiagnostic, and a left anterior thoracotomy was performed, revealing a large yellow, granular-appearing mass in the left upper lobe anterior segment, which was biopsied, and two smaller lingular masses, which were excised with a rim of surrounding lung tissue. The nodules were circumscribed and exhibited a yellow color with soft, necrotic areas with surrounding hemorrhagic, somewhat gray pulmonary parenchyma. Routine hematoxylin-eosin-stained sections revealed necrotic, calcifying granulomas with rare multinucleated giant cells and a predominantly histiocytic and minimal lymphocytic response (Fig 2). In areas the necrotic and calcifying tissue merged with the foamy acellular eosinophilic exudate typical of P carinii pneumonia. In the surrounding lung tissue, this exudate was found in a peculiar perivascular distribution, and occasionally filling pulmonary interstitium, flanked on one side by hyperplastic type II alveolar pneumocytes and on the other by capillary endothelium; occasional alveolar spaces also contained the exudate (Fig 3). Grocott methenamine silver stains revealed numerous cysts of P carinii both within the foamy exudate and within the areas of necrosis and calcification. The organisms in the calcified areas exhibited lighter silver staining than those in other areas, possibly implying their presence for a longer time than those staining darker. Stains for acid-fast bacilli were negative. The patient received a three-week course of trimethoprim-sulfamethoxa-zole with subsequent resolution of symptoms.
Figure 1. Computerized tomography of chest (case 1) showing pulmonary nodule.
Figure 2. Low-power photomicrograph (case 1) of well-defined nodule in pulmonary parenchyma (left side) composed of calcifying, necrotic tissue, areas of foamy exudate, and granulomatous response (center). (Hematoxylin-eosin, original magnification x20.)
Figure 3. High-power photomicrograph (case 1) of pulmonary parenchyma immediately surrounding nodule in Figure 2, revealing both intra-alveolar and adjacent interstitial (arrow) foamy eosinophilic exudate containing Pneumocystis carinii cysts. (Hematoxylin-eosin X 100.)
Tags: AIDS, biopsy, carinii pneumonia