Hyaline membrane disease

This disease, associated with surfactant deficiency in premature infants, is characterized by eosinophilic hyaline membranes lining the airspaces, bronchioles, and alveolar ducts. There is little inflammatory reaction. Hyaline membranes are composed of necrotic debris from type II pneumocytes mixed with fibrin. Similar membranes can be seen in older patients, who are not surfactant deficient, such as term newborns if they suffer diffuse alveolar damage; e.g. in perinatal asphyxia with shock lung.

If hyaline membranes form in a patient who also has severe hyperbilirubinemia, they will take show bile staining.  This is now rarely seen due to lesser frequency of both hyaline membrane disease and severe hyperbilirubinemia. In this case, pneumonia was also present as indicated by neutrophils in the airspaces.