Unclassified sudden infant death associated with pulmonary intra-alveolar hemosiderosis and hemorrhage

The significance of severe pulmonary intra-alveolar hemosiderosis in sudden infant death is controversial in forensic pathology. We report a previously healthy 9-month-old female infant who died suddenly and unexpectedly after being placed and then found prone in her crib. Her gestation and delivery were uncomplicated, and she had no history of anemia, hemoptysis, chest trauma, or chronic lung disease. Autopsy revealed diffuse severe pulmonary congestion and severe multifocal intra-alvedar hemorrhage. Metabolic and toxicological screening, microbiologic cultures, and vitreous chemistry were noncontributory. A diagnosis of SIDS had been made by the medical examiner. Subsequent semiquantitative assessment of the severity of pulmonary intra-alveolar hemosiderosis prompted consideration of other disorders, including a heretofore undescribed lethal infantile variant of idiopathic pulmonary hemosiderosis, but none could be confirmed. Therefore, we assigned a study diagnosis of unclassified sudden infant death. We recommend that a diagnosis of SIDS not be made in cases with unexplained large numbers of intra-alveolar PS. We also recommend that quantitative assessment of lung sections stained for iron be undertaken in cases with numerous intra-alveolar macrophages in order to accumulate data that might allow diagnostic correlations with the circumstances of death and autopsy findings.