What would be an appropriate special stain to order on a bronchoalveolar lavage from a patient with suspected alveolar hemorrhage?
Prussian iron
Oil red O
Gomori methanamine silver
Periodic Acid Schiff-diastase
Show Answer and Explanations
Prussian iron — Correct answer
Correct. Prussian iron would stain hemosiderin-laden macrophages, suggestive of alveolar hemorrhage.
Oil red O
Incorrect. Oil red O would stain lipid. Positive staining in macrophages suggests lipoid pneumonia.
Gomori methanamine silver
Incorrect. GMS would stain fungal organisms.
Periodic Acid Schiff-diastase
Incorrect. The amorphous extracellular material in alveolar proteinosis is PAS positive, diastase resistant.
Summary
Summary: Prussian iron stain helps to identify hemosiderin-laden macrophages in BAL specimens. At least 20% hemosiderin-laden macrophages is highly sensitive and specific for alveolar hemorrhage.