The new ANDI classification is well suited to describe mammary hypertrophy. From normal breast volume to simple hypertrophy, or to major hypertrophy like gigantomastia, all the stages from normal development to the pathological disease can be described.

Mammary Hypertrophy: Developmental Aberration
Mammary hypertrophy, which is a simple exaggeration of normal breast volume, can be embarrassing and the source of psychological problems. It can be physically uncomfortable and the source of vertebral disturbances.

Clinically, the mammary gland is voluminous but supple. Medical treatment with 19-nortestosterone derivatives has been proposed 15 to 10 days per cycle with good results. The decision of surgical treatment can be made without regard to age.

Gigantomastia: Disease
Gigantomastia is a pathological situation whose sudden appearance and rapid progression make it an emergency. It is a sudden increase in mammary volume that occurs early in reproductive life. Sometimes, the gigantomastia is asymmetric. The breasts are firm and painfully strained with inflammatory signs on the breast skin.

Reported for the first time by Durston in 1669, no etiology can fully explain this phenomenon. Classically, hypersensitivity to estrogens has been evoked, but estrogen receptor concentration is normal and plasma estradiol levels are normal. A process of immune dysfunction has been suggested (especially in the presence of inflammatory signs) because hypertrophy may occur in women with autoimmune diseases like rheumatoid polyarthritis, Hashimoto thyroiditis or myasthenia.

Reduction surgery is often necessary to relieve these young women. The ideal time for treatment is once the disease has been stabilized. After surgery, follow-up is desirable because recurrences have been described, leading to mastectomy with mammary prosthesis if the recurrence is major.