Amylase crystalloids in a cystic lesion of the parotid gland diagnosed by and #64257;ne needle aspiration cytology

Abstract

Several types of crystalloids, including tyrosine, collagenous, intraluminal, and amylase crystalloids, may be encountered in fine-needle aspiration biopsy (FNAB) of salivary glands. They have been reported in benign and malignant lesions of the salivary glands. Amylase crystalloids mainly found in benign salivary gland lesions. Microscopic identification of the crystalloids are made according to differences in structural appearance. As it can helpful in differential diagnosis of benign and malignant salivary gland lesions, it is important to identify types of crystalloid. In this report, a 73-year-old man with painless mass in the left parotid gland is presented. Ultrasonographic examination demonstrated a well-defined, hypoechoic lesion in the tail portion of left parotid. Microscopic examination of smears revealed many non-birefringent, rectangular, rhomboid and rod-shaped with parallel sides crystalloids varying in size. Crystalloids stained pink with Hematoxylin & Eosin (H&E), bright orange with Papanicaloau (PAP), and deep blue with May Grunwald Giemsa (MGG). Inflammatory cells and rare benign ductal epithelial cells were observed in a mucoid background. The cytopathological diagnosis was reported as benign non-specific cystic lesion with amylase crystalloids. Since amylase crystalloids are only seen in benign lesions of the salivary glands, it is important to distinguish between amylase and the other crystalloids.