Polycystic disease of the parotid glands

A 31-year-old woman had bilateral swelling of the parotid glands at 4 months of pregnancy. MR imaging showed marked enlargement of the parotid glands with increased signal on images with long repetition times. A diagnosis of polycystic disease of the parotid gland was made after biopsy and histologic examination. The radiographic and histologic features of this rare disease are discussed.