Print version ISSN 0104-4230
Rev. Assoc. Med. Bras. vol.58 no.2 São Paulo Mar./Apr. 2012
IMAGE IN MEDICINE
Izabel Athayde SalgadoI; Charlene Cavalcante SantosII; João Victor SalgadoIII; Patrícia Consorte FerrazIV; Denise Maria HaidarV; Hilda Almeida PereiraVI
ISpecialist in Pediatry; Pediatric Infectology Resident, Universidade Federal do Maranhão (UFMA), Parasitological and Infectious Diseases Service, Hospital Universitário Materno-infantil, UFMA, São Luís, MA, Brazil
IISpecialist in Neonatology, UFMA, Neonatology Service, Hospital Universitário Materno-infantil, UFMA, São Luís, MA, Brazil
IIIMSc in Health Sciences, Universidade de Brasília (UnB); Clinical Analysis Service, Hospital Universitário, UFMA, São Luís, MA, Brazil
IVMedicine Student, UFMA, Hospital Universitário Materno-infantil, São Luís, MA, Brazil
VMSc in Health Sciences, UFMA; Pediatric Pneumology Service, Hospital Universitário Materno-infantil, UFMA, São Luís, MA, Brazil
VISpecialist in Neonatology, UFMA; General Pediatry Service, Hospital Universitário Materno-infantil, UFMA, São Luís, MA, Brazil
Lipoid pneumonia (LP), also known as pulmonary steatosis or pulmonary lipidosis, is an uncommon chronic inflammation of the lung parenchyma with interstitial involvement caused by the accumulation of oily material in the alveoli. Chronic constipation is a common symptom in pediatrics, and physicians often use mineral oil to treat intestinal constipation in children. The accidental aspiration of lipid formulations is the most frequent cause of exogenous lipoid pneumonia in pediatrics1.
The radiological feature of the lipoid pneumonia can mimic many other lung diseases, including infections and carcinoma. Diagnosis of the lipoid pneumonia is often delayed or missed due to the nonspecific clinical manifestation and radiological appearances1. Given this scenario, a report on a patient with a history of chronic constipation and mineral oil ingestion is presented.
A four-month-old boy was admitted to Hospital Universitário Materno-infantil (Universidade Federal do Maranhão) presenting diarrhea (frequency of 10 evacuations a day with mucus, without blood), increasing of abdominal volume, fever, and vomiting for 10 days. The patient had a history of meconium ileus, evacuating for the first time within ten days. After the initial 10 days, the patient had persistent difficulty in evacuation. Due to these circumstances, his mother had been administering mineral oil.
In addition, he was presenting cough without secretion and tachypnea for two days. He was exclusively breastfed, and his scheduled vaccines were completed. At the physical exam he was slightly pale, with tachypnea (requiring 5 L/min of mask oxygen 60%), dehydration, cyanosis, and jaundice; although feverless. Pulmonary auscultation showed a rude vesicular breath sound with softer rhonchi. In the laboratory exams, leukocytosis (66.8% neutrophils, 26.0% lymphocytes), positive C-reactive protein, 8.85 g/dL of hemoglobin, and serum protein of 4.1 g/dL (albumin: 2.9 g/dL and globulin: 1.2 g/dL) were found. Chest radiography showed an infiltrate in the apical regions in both lungs (Figure 1). The first diagnosis was community-acquired pneumonia. Thus, empiric antibiotic therapy was started with ampicillin gentamicin (5 mg/kg/day). Four days later, his intestinal presentation had improved, but he still presented crackles and rhonchi in the pulmonary auscultation. Thirteen days later, he started presenting febrile peaks and a new chest radiograph was requested, still showing opacities in the parenchymal of both lungs (Figure 1).
One week later, he was having daily febrile peaks despite the antibiotics. Requests were made for a chest computed tomography (CT); a gastric lavage for tuberculosis research (three samples), which came negative; and another hemogram and CRP, that were normal. CT showed extensive consolidations and geographic ground glass opacities in both lungs, without any hilar lymphadenopathy, volume loss, mass, or airway compression (Figure 2).
Bronchoscopy with bronchoalveolar lavage (BAL) was performed and 10 mL of an opalescent fluid were divided in three samples. The samples were centrifuged and then analyzed using hematoxylin and eosin staining.
The microscopic exam showed amorphous material, with inflammatory, red blood, cylindrical, and epithelial cells isolated and grouped. The exam also displayed frequent macrophages, some of then xanthomized and with lipid vacuoles (Figure 3). Thus, with the bronchoscopy, the diagnosis of LP was made. Our patient was in a stable condition and therefore discharged from hospital one month later, but with instructions to take prednisone 1 mg/kg/day for 30 days. Follow-up was conducted at the hospital pulmonology service. The follow-up chest radiographies showed a partial decrease of the parenchymal lesion, and the child was in good condition, without any clinical manifestations.
Lipoid pneumonia can be classified as endogenous, idiopathic or exogenous. Endogenous LP, also called cholesterol pneumonitis, is less frequent and generally observed in patients with chronic bronchial obstruction of the airways by tumors, bronchiolitis obliterans, and lipid storage diseases such as Gaucher's disease and Niemann-Pick disease. Idiopathic LP is a rare disorder and has been associated with smoking in healthy individuals. Although exogenous LP is well documented in both pediatric and adult medical literature, it also occurs in the pediatric population as a rare condition caused by aspiration of mineral, vegetable, or animal oils. The use of mineral oil in the treatment of constipation or as an adjuvant treatment for partial bowel obstruction by Ascaris lumbricoides has been well accepted because of its efficacy and infrequent side effects1-3.
In general, children present a widespread acute aspiration condition which progresses to respiratory failure and, sometimes, death. The presence of increasing dyspnea, cough, chest pain, fever, and vomit, together with alveolar infiltrates in the chest X-rays and the previous accidental ingestion of an oily substance, should be cause for suspicion of exogenous lipoid pneumonia. Moreover, the presence of oil in the lungs predisposes to recurrent infections, and in rare cases can be complicated by atypical mycobacterial and cryptococcal infection. These infections result in a bronchoalveolar macrophage response, followed by the release of inflammatory mediators, leading to fever, leukocytosis, neutrophilia, and elevated erythrocyte sedimentation rate. Due to its nonspecific clinical presentation and radiographic signs, exogenous LP can mimic other pulmonary diseases, such as bacterial pneumonia, tuberculosis, cystic fibrosis, bronchiectasis, and tumors2,4,5.
Currently, analysis of the bronchoalveolar lavage (BAL) fluid is considered the diagnostic method of choice for suspected cases of LP, and only the cytochemical examination using staining can confirm the diagnosis6. Both high resolution computed tomography (HRCT) and magnetic resonance imaging have showed suggestive signs of lipid infiltration of pulmonary parenchyma. However, HRCT is the best imaging modality for the diagnosis of exogenous LP5,7,8.
In a recent review article, Marchiori et al.5 reported that there are still no studies in the literature that establish the best therapeutic option for LP. Nevertheless, the key procedure is interrupting the use of mineral oil, which leads to significant clinical improvement. Due to the fact that the depuration of the inhaled oil is a slow process, the best therapeutic strategy would be to withdraw the oil as soon as possible through bronchoscopy with multiple BALs6.
Gondouin et al.9, in a retrospective multicenter study, found that corticosteroid therapy has not been very effective for all cases of lipoid pneumonia. The use of systemic corticosteroids in patients without clinical symptoms remains controversial. However, whole lung lavage, thoracoscopy with surgical debridement, and systemic corticosteroids have been used in patients with diffuse pulmonary damage. Corticosteroid therapy has also been suggested in cases in which functional and radiological alterations continue despite clinical improvement5,10. Even though some retrospective case series demonstrated no benefit in the use of corticosteroids, the patient had a good response after this therapy, and remained asymptomatic at follow-up visits.
The present case emphasizes the need for increased awareness among caregivers and pediatricians about the potential hazards of mineral oil use for chronic constipation. Currently, despite no consensus on treatment, bronchoalveolar lavage seems to be an efficient therapeutic measure for the clearance of mineral oil from the lung parenchyma. This procedure may contribute to preventing fibrosis and reducing the morbidity of lipoid pneumonia, which remains a rare diagnosis.
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2. Khilnani GC, Hadda V. Lipoid pneumonia: an uncommon entity. Indian J Med Sci. 2009;63(10):474-80. [ Links ]
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6. Sias SM, Daltro PA, Marchiori E, Ferreira AS, Caetano RL, Silva CS, et al. Clinic and radiological improvement of lipoid pneumonia with multiple bronchoalveolar lavages. Pediatr Pulmonol. 2009;44(4):309-15. [ Links ]
7. Marchiori E, Zanetti G, Mano CM, Irion KL, Daltro PA, Hochhegger B. Lipoid pneumonia in 53 patients after aspiration of mineral oil: comparison of highresolution computed tomography findings in adults and children. J Comput Assist Tomogr. 2010;34(1):9-12. [ Links ]
8. Betancourt SL, Martinez-Jimenez S, Rossi SE, Truong MT, Carrillo J, Erasmus JJ. Lipoid pneumonia: spectrum of clinical and radiologic manifestations. AJR Am J Roentgenol. 2010;194(1):103-9. [ Links ]
9. Gondouin A, Manzoni P, Ranfaing E, Brun J, Cadranel J, Sadoun D, et al. Exogenous lipid pneumonia: a retrospective multicentre study of 44 cases in France. Eur Respir J. 1996;9(7):1463-9. [ Links ]
10. Russo R, Chiumello D, Cassani G, Maiocchi G, Gattinoni L. Case of exogenous lipoid pneumonia: steroid therapy and lung lavage with an emulsifier. Anesthesiology. 2006;104(1):197-8. [ Links ]
Izabel Athayde Salgado
Rua das Limeiras, qd.D, casa 17, São Francisco
CEP: 65075-260, São Luís - MA, Brazil
Phone: +55 (98) 3235-2888 - Fax: +55 (98) 2109-8026
Study conducted at Hospital Materno-infantil, Universidade Federal do Maranhão, São Luís, MA, Brazil