Sclerosing adenosis of the breast

Dr Henry Knipe and Radswiki et al.

Sclerosing adenosis (SA) is a benign (non-cancerous) proliferative condition of the terminal duct lobular units characterised by an increased number of the acini and their glands. It is sometimes placed under the category of borderline breast disease.

In women with sclerosing adenosis, multiple small, firm, tender lumps (called nodules); fibrous tissue; and sometimes small cysts (i.e. sacs filled with fluid or semi-solid material) form in the breast. 

Clinical presentation

Many women with sclerosing adenosis experience recurring pain that tends to be linked to the menstrual cycle.

In most cases, sclerosing adenosis is detected during routine mammograms or following breast surgery. Usually, a biopsy (i.e. examination of a sample of tissue under the microscope) is required to confirm the diagnosis, because the condition is otherwise difficult to distinguish from breast cancer.

Sclerosing adenosis can appear as focal or diffuse and clinically it is not palpable in 80% of the cases, while in some cases, it might cause skin retraction.


Sclerosing adenosis is a type of adenosis in which enlarged acini become slightly distorted by surrounded stromal fibrosis (sclerosing adenosis). Adenosis and sclerosing adenosis retain the lobular architecture, but it becomes exaggerated and distorted.


Sclerosing adenosis can be seen as a component of other proliferative lesions, such as:

Radiographic features


On mammography, sclerosing adenosis may consist of architectural distortion, amorphous microcalcifications (which can be present in 40-55% of cases 5,6), or both. At times a mass lesion or asymmetrical density may be present. It can be therefore very difficult to mammographically distinguish from an infiltrating carcinoma.

Treatment and prognosis

It is considered an independent risk factor for development of subsequent breast cancer 3. Clinical research suggests that women with sclerosing adenosis may have approximately 1.5-2 times as high a risk of developing breast cancer.  

Related articles

Breast imaging and pathology

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