Gestational gigantomastia is a rare disorder characterized by rapidly progressive hypertrophy of the breast tissue during pregnancy. Its prevalence is approximately 1:100,000, and although the etiology of this condition remains unclear, it may be related to hormonal change. This study reports the case of a 39-year-old pregnant woman at 22 weeks of gestation with massive enlargement of bilateral breasts (gigantomastia) and presents the sonographic findings of this rare condition which shows different parenchymal patterns from those of normal breasts and is uncommonly seen.

Keywords: Gestational gigantomastia, Mammary duct hyperplasia, Reduction mammoplasty