Educational aims are the discussion of the radiologic, histopathologic and clinical association of PAP and pulmonary tuberculosis in a case. A 46-year-old, life long non-smoker male was admitted to the hospital with the complaints of dyspnea, cough and fever. He had fatigue, non-productive cough and progressive dyspnea during two months and fever for a week. He is working as a welder. His medical history was normal. Physical examination revealed the bilateral fine crackles. The purulent sputum was

present. Chest roentgenogram demonstrated the bilateral alveolar and interstitial opacities with paracardiac non-homogenous opacity on right hemithorax (Fig. 1A). The hemoglobin value was 10.1, peripheral blood leukocyte count was 12,000 cell/cu mm and erythrocytes sedimentation rate was 60 mm/h. Arterial Antidiabetic Compound Library cell line blood gas values during room-air breathing revealed that the pH: 7.52, pO2: 60 mmHg, pCO2: 24 mmHg and SaO2:

94%. Other laboratory values were normal. Thorax CT revealed the bilateral ground-glass opacities associated with thickened click here interlobular septa, called to as “crazy paving” pattern (Fig. 2). Also, alveolar consolidation was observed on right middle lobe. Fiberoptic bronchoscopy showed the hyperemic bronchial mucosa. AFB-staining and cytological examination of bronchial lavage fluids were negative and benign, respectively. Transbronchial biopsy was performed. Histopathologic examination of transbronchial biopsy showed the alveolar spaces filled with granular eosinophilic materials which were Periodic acid-Schiff (PAS) positive (Fig. 3). The patient wanted to get discharged on 2nd day of hospitalization and he did not want to receive any treatment. Ten days later, he was admitted to the hospital Carnitine palmitoyltransferase II with fever. Chest radiograph on second admission was similar to the first admission. The direct smear of the sputum

showed acid-fast bacilli with AFB-staining. The culture of previously taken bronchial lavage fluid grew Mycobacterium tuberculosis. Antituberculosis treatment combined with regimen of isoniazid, morfozinamid, rifampicin and ethambutol was started. The symptomatic and radiologic improvements were observed after the treatment (Figs.  1A and 4). Pulmonary alveolar proteinosis (PAP) is a rare and diffuse lung process, etiology undetermined, characterized by the presence of alveolar spaces filled with amorphous eosinophilic material.1 and 4 The accumulation in alveolar spaces is probably caused by defective clearance of lipoproteinaceous material by alveolar macrophages. Recent animal experiments have suggested that GM-CSF (granulocyte-macrophage colony stimulating factor) deficiency might play a role in the pathogenesis.5 and 6 Secondary PAP could be associated with 3 main clinical settings: Infection of the lung, most commonly with Norcardia astroides, TB, Mycobacterium avium-intracellulare, or P. carinii. Hematologic malignancies and other conditions that alter the patient’s immune status, e.g.