Altered breast density between two mammograms

Altered density between two mammograms can arise in a number of situations

Can affect both breasts

• interval commencement / cessation of hormone replacement therapy: there is a definite and noticeable increased breast density visible on mammography when patients are on hormone replacement therapy. The changes reverse on cessation of therapy.
• lactation: in practice ultrasound is the imaging modality of choice during lactation. The patients are young and the increased density of the breast during lactation makes practical use of conventional mammography only useful in selected cases.
• worsening / resolution of congestive cardiac failure
• worsening / resolution of fluid overload from other causes 
• substantial weight loss / weight gain: this is an important cause. Significant changes in the body mass index have a profound impact on the density of breasts on mammography. if there is a significant mass change, a technologist note should be made.
• interval precipitation of SVC syndrome
• idiopathic granulomatous lobular mastitis (IGLM)
• medications : e.g Danazol : decreases density
• vitamin D and calcium intake in pre-menopausal women : decreases density
• increasing age : decreases density. Involution of the breast implies that the ratio gland: fat decreases.  The patient's breast glandular tissue involutes as the hormonal changes associated with ageing take place. The  breast becomes progressively more fatty replaced. The upside is that clinical symptoms associated with ANDI tend to resolve.

Can affect one breast

• radiation therapy effects: this is an important etiology. The changes seen after breast radiation affect the radiated breast only. There is a global, diffuse increase in breast density that continues to change even after the radiation has been stopped. Watch too for the subtle skin changes seen at the same time. The skin appears to thicken slightly on compression.
• lymphatic blockage
• malignancy : e.g invasive lobular carcinoma especially if affecting part of the breast

See also

• breast density