Massive Hypertrophy

The main symptom of gigantomastia is an excessive overgrowth of breast tissue in one breast (unilateral) or both breasts (bilateral). The growth may occur slowly over a period of a few years. In some women, the breast growth occurs rapidly over the course of just a few days or weeks.

There is no universally accepted definition for the amount of growth. Many researchers define gigantomastia as a breast enlargement that requires reduction of 1,000 to 2,000 grams per breast. https://www.healthline.com/health/gigantomastia#symptoms