A case report of exogenous lipoid pneumonia associated with avocado/soybean unsaponifiables
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Exogenous lipoid pneumonia is a rare disease resulting from intra-alveolar accumulation of lipids of mineral, vegetal, or animal origin, that induce a foreign body type of inflammatory reaction in the lungs. Gastroesophageal reflux disease and other esophageal abnormalities have often been associated with this disease.
We herein report the case of an 83-year-old patient in whom a follow-up chest computed tomography scan, for a lingular consolidation, showed multifocal ground glass and consolidative opacities with areas of low attenuation, suggestive of exogenous lipid pneumonia. The patient had been on piascledine capsules (avocado/soybean unsaponifiables) for 20 years and had a hiatal hernia with documented gastroesophageal reflux disease. After thorough history taking, no other predisposing factors were found. The diagnosis was confirmed using oil red staining of bronchoalveolar lavage showing lipid-laden macrophages and extracellular lipid droplets.
To our knowledge, this is the first case of ELP secondary to avocado/soybean unsaponifiables in the literature.
KeywordsExogenous lipoid pneumonia Avocado oil Soybean oil Hiatal hernia Gastroesophageal reflux disease
Exogenous lipoid pneumonia
Gastroesophageal reflux disease
Left upper lobe
Positron emission tomography – computed tomography
Pulmonary function tests
Exogenous lipoid pneumonia (ELP) is a rare lung condition due to the inflammatory reaction generated by the presence of foreign fatty substances in the alveoli. ELP can be suspected when a clinical history of inhalation or aspiration of fatty substances and chest imaging are compatible [1, 2, 3]. Confirmation of the diagnosis requires special staining of bronchoalveolar lavage (BAL) fluid or lung biopsies [4, 5]. We present an unusual case of ELP caused by avocado/soy unsaponifiables (ASU).
After confirmation of the diagnosis, in the absence of other fatty-substance exposure, a presumptive diagnosis of ELP caused by ASU aspiration in a patient with GERD was established. This treatment was stopped. No surgical treatment of her hiatal hernia was suggested in this patient who had refused invasive procedures. One year later, the patient was clinically stable, her cough regressed and her PFTs normalized. Her chest CT showed persistent lingular consolidation and regression of the ground-glass opacities.
Discussion and conclusions
ELP is an unusual form of pneumonitis, caused by exogenous lipids of mineral, vegetal, or animal origin , reaching the alveoli by inhalation of volatile hydrocarbons [7, 8, 9], or by aspiration of oil-based substances. Most cases of ELP result from mineral oil aspiration found in laxatives and oily nose drops .
Diagnosing ELP is based on a history of exposure to exogenous fat, compatible radiological findings, and a demonstration of lipids in lung biopsy specimens or BAL [1, 6, 10, 13, 14]. In a French case series, GERD was associated with ELP in 50% of cases . Lipids tend to overlay gastrointestinal fluids in static situations, making patients more vulnerable to chronic aspiration of fat, especially in hiatal hernia with GERD . Our patient had typical ELP with a compatible CT scan and BAL. Although it has never been described in the literature, the most probable culprit in this context was the 300 mg non-gastro-resistant capsules of ASU capsules [15, 16, 17]. We consulted the international databases of “Expanscience Laboratoires”, the manufacturer of the drug, looking for similar adverse effect in the drug safety databases, but we did not find any. Although the patient’s cough may arguably have been due to the ELP itself, its nocturnal timing and the GERD-compatible 24-h pH-metry suggested symptomatic nocturnal GERD.
ELP is often insidious, and in our patient, the initial lingular opacity could be an inaugural sign of the disease , even though no low-attenuation areas were seen within it. Both PET scans did not show any abnormal uptake. We currently do not know the value of PET scans in ELP evaluation. Nonetheless, several papers have reported cases of ELP mimicking neoplastic nodules on PET-CT, with moderate uptake of up to 4.4 of SUVmax [18, 19, 20].
Although ELP is uncommon, the pneumologist should have a high degree of suspicion whenever a history and imaging results are suggestive of the disease. Thorough search of the culprit source is essential to reverse the disease. Our case is the first to report ELP caused by ASU, readily commercialized as dietary joint supplements.
December 2017–March 2018
Chest CT: lingular consolidation
Follow-up PET/CT scan: non-hypermeta-bolic lingular consolidation Pulmonary function tests: normal
Follow-up PET/CT scan: persistant non-hypermeta-bolic lingular consolidation
Clinically: dyspnea and cough
Chest CT: lingular consolidation compatible with lipoid pneumonia Bronchoscopy with broncho-alveolar lavage: compatible with lipoid pneumonia
Pulmonary function test: restrictive pattern.
pH-metry: compatible with GERD Decision: stop treatment with avocado/soybean unsaponifiables
Clinically: improvement Chest CT: regression of ground-glass opacities. Persistence of lingular consolidation Pulmonary function test: normal
JB1, MM, JB2, ML CHM, YD, BP, VH and SL were involved in the clinical care of the patient. FR was responsible for the pharmacovigilance investigation. All contributed to and approved of the final manuscript. The datasets used and/or analyzed during the current study available from the corresponding author on reasonable request.
Ethics approval and consent to participate
Consent for publication
Written informed consent for publication of their personal or clinical details and/or clinical images was obtained from the patient.
The authors declare that they have no competing interests.
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