Fibrocystic Disease

Fibrocystic Disease

·        A „catch-all‟ category for gross and micro cysts

·        Don‟t call it mammary dysplasia

·        Commonest disease of the breast

·        Cause obscure – unopposed oestrogen a known factor. Women on combined pill get less fibrocystic disease

·        Classification by size:

o   Gross cysts: very easy to diagnose on US.  40s.  Drain with FNA

o   Micro cysts: usually 30‟s and 40‟s.  May have cyclical pain.  Resolves after menopause

o   Galactocoele – milk filled cyst, usually with lactation

·        5 components (either separately or together):

o   Cysts:

§  Dilated ducts containing cloudy serous fluid (sometimes bloody or infected)

§  All breasts contain microcysts during childbearing years.  Abnormal when > ~ 2mm 

§  Histology: epithelium may be flattened, cuboidal, columnar, piled up or show apocrine metaplasia. Surrounding stroma likely to be fibrous

o   Fibrosis:

§  Dense collagenisation distorting/compressing epithelial structures

§  Most common in upper outer quadrants, patient‟s in 30s

o   Sclerosing adenosis:

§  Usually a tender lump in the upper outer quadrant, patient around 40

§  Benign proliferation of small ductules in a fibrous stroma, but histologically circumscribed

§  Lining cells proliferate to fill the ducts

§  Increased risk of cancer with florid (2*) and atypical (4*) hyperplasia

§  Mimics cancer both clinically and microscopically

o   Apocrine Metaplasia: Benign metaplastic change to tall cells with eosinophilic cytoplasm resembling those of secretory glands (eg lactation, sweat, etc)

o   Duct (and sometimes lobular) epithelial hyperplasia