Exogenous lipoid pneumonia superinfected with acid-fast bacilli in infants: a report of nine cases.

Research paper by Cecilia C Ridaura-Sanz, Eduardo E López-Corella, Margarita M Salazar-Flores

Indexed on: 16 Aug '06Published on: 16 Aug '06Published in: Fetal and pediatric pathology


Super-infection of an exogenous lipoid pneumonia by nontuberculous mycobacteria has been described in the literature. It produces a distinctive histologic picture with suppurative, noncaseating granulomas surrounding lipid vacuoles containing acid-fast bacilli. Mainly isolated cases have been found, but seldom in children. We describe a series of 9 children with similar histological findings. All our patients were under 1 year of age, malnourished, and with chronic respiratory symptoms. The diagnosis, based on the characteristic histology with acid-fast rods, was established at autopsy in 4 cases, on lobectomy specimens in 4 and by open lung biopsy in 1. Mycobacterium fortuitum-chelonei was cultured in 1 case. Gastro-esophageal reflux was documented in all 4 cases in which it was explored. Aspiration of lipid gastric contents or of oil given as medication can result in exogenous lipoid pneumonia, which in turn becomes super-infected with mycobacteria. Recognition of the distinctive histology permits the diagnosis of this complication.