A 31-year-old woman had bilateral swelling of the parotid glands at 4
months of pregnancy, MR imaging showed marked enlargement of the parot
id 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 fea
tures of this rare disease are discussed.