G Fontana

Crystal‐storing histiocytosis presenting with pleural disease

accrued in part as referrals for expert opinion. However, the primary goal of the study was to determine whether there were histological features in these biopsy specimens that come from infants with unexplained suspected diffuse parenchymal lung disease that have coexistent vascular abnormalities and that might give prognostic and predictive data in relation to future management; to a limited degree, this is what we achieved. In relation to cases with overlapping features of ACD and CAD, we think it unwise to provide specific clinical criteria, as our view is that this is a spectrum of changes that reflect variable immaturity and disordered growth within the lung. We can only hypothesize that the extent of ACD in such cases reflects poor survival, and the presence of relatively better capillary development in biopsy specimens with CAD suggests an improved chance of survival in these critically ill neonates and infants. The number of cases is small and the evidence is weak, but our study should at least provide a template for accrual of more data.