[Exogenous lipid pneumonia with hyperpyrexia: a case report]

Lipoid pneumonia (LP) is an uncommon form of pneumonia that is characterized by the presence of intra-alveolar lipid and lipid-laden macrophages on microscopy. It categorized as exogenous lipoid pneumonia (ExLP) and endogenous lipoid pneumonia (EnLP). Exogenous lipoid pneumonia caused by inhalation of liposuction substances (animal fat, vegetable oil, or mineral oil), mostly, in adult cases, they were medicines for constipation or rhinopharyngitis. Most of these patients showed mild clinical manifestations, and chronic medical condition. There were reports of lipoid pneumonia being successfully treated with corticosteroids, immunoglobulins and whole lung lavage. We report a case of exogenous lipoid pneumonia characterized by high fever and acute medical condition. A 77-year-old woman with hypertension and diabetes mellitus, accepted paraffin oil treatment for "incomplete intestinal obstruction", then, an accident of aspiration happened, as she went through the history of coughing while eating, followed by persistent hyperthermia and increases of white blood cells (WBC). Chest CT showed progressive ground-glass opacities, accompanied with fusion of consolidation, her sputum etiological examination was negative, and the therapy of broad-spectrum antibiotic was invalid. The patient was subjected to bronchofibroscopy with bronchoalveolar lavage (BAL). The bronchoalveolar lavage fluid (BALF) appeared colorless and transparent, and did not show a milky appearence. Total cell count of the BALF was 2.0×10⁹ cell/mL, including 7.2% macrophages and 92.8% neutrophils. Cultures of the BALF were negative for bacterial, fungal, and mycobacterial pathogens. The BALF cytologic findings showed vacuolated lipid-laden macrophages (Oil Red O staining). These findings revealed exogenous lipoid pneumonia. There were reports of lipoid pneumonia being successfully treated with corticosteroids, immunoglobulins, and whole-lung lavage. So this patient was treated with methylprednisolone 120 mg/d for 3 days and 80 mg/d for 6 days, at the same time, immunoglobulins was given to infusion, but the daily peak temperature of the patients fluctuated between 38 and 39 degrees. Then, whole lung lavage was performed 28 days after admission. Unfortunately, acute pulmonary edema occurred during the operation, as the tracheal intubation problems, and 6 days later, the patient died at last. The clinical manifestations of exogenous lipid pneumonia vary greatly, from asymptomatic to life-threatening symptoms, and as febrile low fever is the main manifestation, but hyperthermia may also be the remarkable presentation.