Identification of Amylase Crystalloids in Cystic Lesions of the Parotid Gland

OBJECTIVE To identify alpha-amylase crystalloid formations in parotid specimens obtained by fine needle aspiration. STUDY DESIGN The study concerned three cases of sialadenitis with crystalloid formation observed between 1993 and 1998. In one of these cases, transmission electron microscopy, mass spectrometry and measurement of amylase activity were used to characterize the nature of the crystalloids. RESULTS Light microscopy revealed the same crystalloid structure in all three cases. In one case, where the material was saved, a biochemical method made it possible to reveal high amylase activity, while protein electrophoresis and mass spectrometry were used to identify salivary alpha-amylase. CONCLUSION Crystalloids of salivary alpha-amylase can be identified by May-Grünwald-Giemsa and Papanicolaou stain and can be rapidly confirmed through determination of amylase activity.