α-amylase crystalloid granuloma of the parotid gland: case report and review of the literature

We report a case of α-amylase crystalloid granuloma of the parotid gland in a 65-year-old Japanese woman. Histopathologically, the lesion comprised cystlike dilatation of the ducts and foreign body granulomas, with deposits of numerous crystalloid structures. The crystalloids were eosinophilic and varied in size and shape. Immunohistochemically, the crystalloids were positive for α-amylase. Immunoelectron microscopy showed the crystalloids to be cuboidal or rectangular in shape with irregularly shaped central spaces. We discuss this rare condition and review the literature on α-amylase crystalloids.