Mammographic screening detects early breast cancers and thereby reduces potential mortality. However, its sensitivity is inversely related to breast density 1.
Altered density between two mammograms can arise in a number of situations:
Affecting both breasts:
- interval commencement/cessation of hormone replacement therapy: there is 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 as the patients are young and the increased density of the breast during lactation makes mammographic imaging difficult.
- worsening/resolution of congestive cardiac failure
- worsening/resolution of fluid overload from other causes
- substantial weight loss/weight gain: Significant changes in the body mass index have a profound impact on the density of breasts on mammography.
- 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: Involution of the breast implies that the ratio gland: fat decreases thereby decreasing density on mammogram.
Affecting one breast:
- radiation therapy: this is an important etiology for increased breast density which is seen only on the irradiated breast. The changes continue even after the radiation has been stopped.
- lymphatic blockage
- malignancy: e.g. invasive lobular carcinoma especially if affecting part of the breast
- 1.Drukteinis JS, Mooney BP, Flowers CI et-al. Beyond mammography: new frontiers in breast cancer screening. Am. J. Med. 2013;126 (6): 472-9. doi:10.1016/j.amjmed.2012.11.025 - Pubmed citation
- 2. Cardeñosa G. Clinical breast imaging, a patient focused teaching file. Lippincott Williams & Wilkins. (2006) ISBN:0781762677. Read it at Google Books - Find it at Amazon
- 3. Paredes ES. Atlas of mammography. Lippincott Williams & Wilkins. (2007) ISBN:0781764335. Read it at Google Books - Find it at Amazon