EARLY LIPOID PNEUMONIA. ROENTGENOLOGIC, ANATOMIC AND PHYSIOLOGIC CHARACTERISTICS

Squalene-induced extrinsic lipoid pneumonia: serial radiologic findings in nine patients

PURPOSE

The purpose of this work was to demonstrate the initial and follow-up radiologic findings of squalene-induced extrinsic lipoid pneumonia.

METHOD

Follow-up chest radiographs (n = 9) and high-resolution CT scans (n = 3) as well as initial radiographs (n = 9) and CT scans (n = 8) were obtained in nine patients with squalene-induced extrinsic lipoid pneumonia. The serial radiologic findings were analyzed retrospectively by three chest radiologists, focusing on the pattern and distribution of parenchymal abnormalities.

RESULTS

The most frequent pattern of parenchymal abnormalities on chest radiograph was areas of ground-glass opacity (n = 9, bilateral 6), followed by consolidation (n = 7, bilateral 3) and poorly defined small nodules (n = 4, bilateral 2). The abnormalities were distributed in the right lower lung (n = 9), left lower lung (n = 6), and right middle lung (n = 6) zones. Initial CT scans (n = 8) demonstrated bilateral areas of ground-glass attenuation (n = 8), poorly defined centrilobular nodules (n = 8), crazy paving (n = 6), and consolidation (n = 3). The abnormalities were distributed in the right middle lobe (n = 8) and in both lower lobes (n = 5). Follow-up chest radiograph (n = 9) showed complete disappearance (n = 2) and decrease (n = 7) in the extent of the parenchymal abnormalities. Follow-up CT scans (n = 3) demonstrated decrease (n = 2) and no change (n = 1) in the extent of the abnormalities.

CONCLUSION

Squalene-induced extrinsic lipoid pneumonia most commonly appears as areas of ground-glass attenuation mixed with poorly defined centrilobular nodules and crazy paving on CT, being distributed mainly in the right middle and both lower lobes. The lesions are indolent and remain after cessation of squalene ingestion.

Shark liver oil-induced lipoid pneumonia in pigs: correlation of thin-section CT and histopathologic findings

PURPOSE

To evaluate sequential changes in thin-section computed tomographic (CT) findings after inducement of lipoid pneumonia and provide the histopathologic bases of these findings.

MATERIALS AND METHODS

Shark liver oil was administered to 12 sites in seven pigs. Thin-section CT scans were obtained within 1 hour and at 1 week, 2 weeks, 4 weeks, 8 weeks, 12 weeks, and 16 weeks after oil administration. Scans were assessed for opacity, distribution, location at the lobular level, extent, and volume of the lesions. The CT number in consolidation areas also was measured. Findings at CT were correlated with those in the histopathologic specimens.

RESULTS

Diffuse ground-glass opacity was noted on all immediately obtained scans. The opacity of the lesions was highest at 1 week; then it decreased gradually to an area of ground-glass opacity. The extent and volume of the lesions decreased at follow-up CT. Histopathologically, the lesions showed a lobular distribution sharply demarcated from the normal lungs. The lobules of decreased volume showed residual thickening of the alveolar walls with bronchiolectasis and mild collagen deposition of the interlobular septa. Pathologic examination of the low-attenuating consolidation area at CT revealed evidence of partial aeration.

CONCLUSION

Thin-section CT findings of lipoid pneumonia include ground-glass opacity and airspace consolidation, followed by complete or incomplete resolution with volume loss and septal thickening. Low-attenuating consolidation at CT does not always indicate the presence of fat.

Interstitial pulmonary disease induced by occupational exposure to paraffin

An occupational interstitial pulmonary disease was observed in a 59-year-old workman after five years of massive exposure to aerosolized paraffin. Histologic studies of open-lung biopsy showed a lipoid pneumonia characterized by (1) alveolitis involving large lipid-laden macrophages and (2) interstitial fibrosis. Electron microscopy of AMs disclosed features of paraffin-laden cytoplasmic vacuoles. Successive treatments included prednisolone and cyclophosphamide. Despite these treatments and withdrawal from exposure, the pulmonary function became impaired progressively, resulting in restrictive syndrome and severe exertional dyspnea. Concomitantly, PMNs harvested by BAL increased, whereas initial lymphocytosis decreased. This is the first case observed of occupational interstitial fibrosis in which electron-microscopic findings clearly established a relationship with an exposure to paraffin. This observation also emphasizes the switch from alveolitis to fibrosis in the pathogenesis of interstitial pulmonary disease.

Radiographic plain film and CT findings in lipoid pneumonia in infants following aspiration of mineral oil used in the treatment of partial small bowel obstruction by Ascaris lumbricoides

Four children developed lipoid pneumonia following ingestion of mineral oil for the treatment of partial small bowel obstruction by Ascaris lumbricoides whorl. CT of the chest showed negative Hounsfield numbers which may prove useful in diagnosis.

Lipoid pneumonia: an occupational hazard of fire eaters

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Exogenous lipoid pneumonia

Eleven patients with exogenous lipoid pneumonia are reported. A history of usage of oil was obtained in all, but in five only retrospectively after thoracotomy. The clinical presentations ranged from occasional cough to severe respiratory difficulties. The radiologic manifestations varied from a solitary lipoid granuloma and larger consolidations simulating carcinoma to extensive subacute bronchopneumonia. The definitive diagnosis was made by history and radiographic findings in three, by history and analysis of sputum or bronchial washings in two, and after thoracotomy in six.

Upper airway problems in industrial workers exposed to oil mist

Exposure to oil mist used in metal work sometimes gives symptoms from skin and airways. This study was performed to evaluate histological and functional respiratory tract disorders. Six male lathe workers aged 31-64 years exposed to oil mist for 4-29 years were examined and compared with matched controls. The investigation included case history, ENT examination, nasal mucociliary function, routine blood tests, IgE, RAST, X-ray of sinus and lungs and biopsy of the nasal mucosa. The mucociliary test showed no difference between the groups. However, all 6 exposed workers had pathological histology findings in the nasal mucosa including lack of cilia, basal cell hyperplasia, goblet cell hyperplasia, squamous metaplasia and subepithelial hyalinization. The biopsies from the controls were mainly normal. The remainder of the investigations revealed no pathology. The study shows that exposure to oil mist--even below the permitted threshold limit--may cause airway symptoms and histological signs comparable to a premature ageing.

Drug-induced pulmonary disease

Pulmonary disorders appearing as manifestations of adverse reactions to medications administered orally or parenterally are reviewed. The mechanisms involve toxicity, idiosyncrasy, allergy, or a combination. The drugs and medications include commonly used antimicrobial, antineoplastic, analgesic, vasoactive, neuroactive, and endocrine agents. For most reactions, the mechanisms are unidentified.

A case of chronic paraffin pneumonitis

A case of chronic paraffin pneumonitis is reported which had remained undiagnosed during life. The patient, a woman aged 48 at death, was subsequently found to have been taking regularly very large doses of liquid paraffin during a decade or more. The main clinical, radiological and histological features are discussed.