Exogenous lipoid pneumonia induced by nasal decongestant.

Introduction: Lipoid pneumonia is a clinical condition that may be initially asymptomatic or confused with an infectious or malignant lung disease.

Objectives: We report four cases of this pathological condition.

Methods: The first case concerned an 85-year old woman with bilateral confluent pulmonary opacities, ground-glass type. Diagnosis was based on the cytology of the bronchoalveolar lavage (BAL) fluid followed by its ultrastructural examination. The second case was a 47-year-old man with an isolated pulmonary nodule, which was surgically removed; the diagnosis of lipoid pneumonia was formulated on the basis of the histological and electron microscopy examination. The third case concerned a 73-year-old woman, with bilateral hypodense areas at the bases of the lungs where FDG PET/CT scan showed an increased uptake. Diagnosis was formulated by BAL cytology and electron microscopy examination. The fourth case was a 69-year-old man, who performed a virtual colonoscopy for diverticulosis putting in evidence a round mass (3 cm in diameter) with two small peripheral nodules, located in the pulmonary left lower lobe. The histopathological examination of transthoracic biopsy confirmed a lipoid pneumonia.

Results And Conclusion: In all four cases, it was put in evidence a prolonged use of a nasal decongestant containing mineral oils. In literature, the most cases described are characterized by a subclinical evolution and were presented as ground glass opacities which evolve, in the later phases, in an interstitial involvement or in a peripheral mass, simulating a lung tumour.