Multidisciplinary approach to suspected sudden unexpected infant death caused by milk-aspiration: a case report

BACKGROUND The term sudden unexpected infant death (SUID) is not always properly invoked. It refers to a broad range of conditions that sometimes defy classification. There is not only a strong emotional impact on the family, but such cases are also quite complex. Underlying causes may be multiple, not always readily apparent, and have potential repercussions, especially in terms of forensics. CASE SUMMARY A 5-month-old male baby was pronounced dead following acute lung failure and cardiopulmonary arrest. The parents had immediately rushed their child to the hospital, stating the baby was found prone and not breathing. Total-body postmortem computed tomography (PMCT) was performed, revealing a hypodense material of indeterminate nature within the main airways and areas of ground-glass parenchymal change. At autopsy, the respiratory tract mucosa appeared edematous and was coated with a whitish stringy material. There was widespread airspace reduction due to parenchymal collapse. Alveolar sacs and bronchial openings contained abundant amorphous material admixed with white blood cells. Immunohistochemical studies were performed, targeting CD15, CD68, and alpha-lactalbumin. Ultimately, the focus was on alpha-lactalbumin (milk protein), which showed marked immunopositivity within alveolar spaces. Cytoplasmic staining of macrophages was also particularly prominent. CONCLUSION Postmortem investigations are thus essential to identify causes of death and surrounding circumstances. PMCT is a useful tool in this setting, given the frequent dearth of autopsy findings and ambiguity as to cause of death in SUID cases. These findings, later confirmed by immunohistochemical investigations, were indicative of active pneumonia due to aspirated milk. The present account illustrates the importance a broad diagnostic approach to SUID in cases of forensic concern. PMCT is a very valuable aid in cases of forensic interest, as it can provide useful information in all those situations in which the cause of death is uncertain or there are no suggestive dynamics or lesions.