Lipoid pneumonia is an uncommon lung condition, usually of insidious onset. This disease has two clinical forms: endogenous and exogenous. Diagnosis is difficult and challenging because this condition is known to mimic many pulmonary diseases clinically and radiographically. We present a patient with a diagnosis of exogenous lipoid pneumonia resulted from occupational exposure to oil mists used in wood finishing at a furniture factory.
33-year-old white female was referred to our clinic with a possible diagnosis of bronchiolitis oblitirans organizing pneumonia (BOOP). She had recurrent symptoms of fatigue, fever, night sweats, and dry cough despite multiple courses of antibiotics and corticosteroids and required multiple hospitalizations. Her chest film demonstrated alveolar filling infiltrates consistent with pneumonia. Patient worked in a cabinet-making factory and was exposed to sawdust as well as wood finishing and paint materials, which contained refined castor oil, linseed oil and petroleum. She had undergone open lung biopsy prior to her clinic visit and the initial report carried a BOOP diagnosis. Bronchoalveolar lavage at our institution revealed a lipid laden alveolar macrophage index of 134 suggesting the possibility of exogenous lipoid pneumonia. Further review of the open biopsy revealed alveolar spaces filled with foamy histocytes consistent with a primary process of lipoid pneumonia and focal areas of BOOP-like proliferation. A cavitary lesion developed at the biopsy site with fluid loculation that required surgical intervention with lobectomy. At this time the patient is feeling well with mild shortness of breath.
Exogenous lipoid pneumonia is a rare lung disease that results from the aspiration and/or inhalation of fat-like substances. Few clinical entities have been described but include; diffuse chronic and acute mineral oil pneumonia as well as parfinomas. Liquid paraffin is the most etiological agent in adults. Occupational exposure to oil mists especially particles 2.5 μm or less can lead to chemical pneumonitis and lipoid pneumonia. The primary treatment is avoidance of the offending agent and using antibiotics for secondary infections. Corticosteroids have been used as an adjunctive therapy. Partial lung resection has been performed in some cases.
Lipoid pneumonia should be suspected in patients with a history of exposure to mineral oils in light of a suspected pneumonia with no clinical or radiological improvement despite broad-spectrum antibiotic therapy.
Y. Huang, None.