Sudden unexpected death in infancy: Severe pulmonary anatomopathological findings in spite of inconsistent clinical features.

Respiratory tract infections play a considerable pathogenetic role in many cases of sudden infant death (SID). Frequently, clinicians encounter difficulties in diagnosing the disease because of its often unspecific clinical and radiological presentation. We report three cases of sudden unexpected death in infancy (SUDI), involving two males and one female admitted to hospital due to mild respiratory distress. In all three cases, complete post-mortem investigations were successful in uncovering interstitial lung disease as the cause of death. These cases highlight the key role of infection-related interstitial lung diseases in the pathogenesis of some currently unexplained SUDI/SIDS and the diagnostic difficulties due to the variable clinical and histological pattern, thereby explaining the importance of performing complete post-mortem investigations whenever an infant dies suddenly and unexpectedly.