Page 771 - Textbook of Pathology, 6th Edition

lobule from the other and is composed mainly of adipose Mammary Duct Ectasia (Plasma Cell Mastitis) 755
tissue and some loose connective tissue. Mammary duct ectasia is a condition in which one or more
The most important disease of the breast is cancer.
However, there are a few inflammatory lesions, benign of the larger ducts of the breast are dilated and filled with
inspissated secretions. These are associated with periductal
tumours and tumour-like lesions which may be confused and interstitial chronic inflammatory changes. Duct ectasia
clinically with breast cancer. These pathologic lesions are affects women in their 4th to 7th decades of life. The patients
described first, followed by an account of breast cancer.
may remain asymptomatic or there may be nipple
discharge, retraction of the nipple due to fibrous scarring
NON-NEOPLASTIC CONDITIONS and clinically palpable dilated ducts in the subareolar area.
The lesion may be mistaken for carcinoma of the breast.
These conditions in the breast include inflammations,
fibrocystic change and gynaecomastia. The etiology of the condition remains unknown but it
appears to begin with periductal inflammation followed by
destruction of the elastic tissue to cause ectasia and
INFLAMMATIONS
periductal fibrosis.
Inflammation of the breast is called mastitis. Important types
of mastitis are acute mastitis and breast abscess, chronic MORPHOLOGIC FEATURES. Grossly, the condition
mastitis, mammary duct ectasia (or plasma cell mastitis), appears as a single, poorly-defined indurated area in the
traumatic fat necrosis and galactocele. breast with ropiness on the surface. Cut section shows
dilated ducts containing cheesy inspissated secretions.
Acute Mastitis and Breast Abscess Histologically, the features are as under:
Acute pyogenic infection of the breast occurs chiefly during 1. Dilated ducts with either necrotic or atrophic lining
the first few weeks of lactation and sometimes by eczema by flattened epithelium and lumen containing granular,
of the nipples. Bacteria such as staphylococci and amorphous, pink debris and foam cells.
streptococci gain entry into the breast by development of 2. Periductal and interstitial chronic inflammation,
cracks and fissures in the nipple. Initially a localised area chiefly lymphocytes, histiocytes with multinucleate histio-
of acute inflammation is produced which, if not effectively cytic giant cells. Sometimes, plasma cells are present in CHAPTER 25
treated, may cause single or multiple breast abscesses. impressive numbers and the condition is then termed
Extensive necrosis and replacement by fibrous scarring of plasma cell mastitis.
the breast with retraction of the nipple may result. 3. Occasionally, there may be obliteration of the ducts
by fibrous tissue and varying amount of inflammation and
Granulomatous Mastitis is termed obliterative mastitis.

Although chronic non-specific mastitis is uncommon, chronic
granulomatous inflammation in the breast may occur as a Fat Necrosis The Breast
result of the following: Focal fat necrosis of an obese and pendulous breast followed
1. Systemic non-infectious granulomatous disease e.g. as part by an inflammatory reaction is generally initiated by
of systemic sarcoidosis, Wegener’s granulomatosis. trauma. The condition presents as a well-defined mass with
2. Infections e.g. tuberculosis which is not so uncommon in indurated appearance.
developing countries like India and may be misdiagnosed
clinically as breast cancer owing to axillary nodal Grossly, the excised lump has central pale cystic area of
involvement. Tubercle bacilli reach the breast by haemato- necrosis.
genous, lymphatic or direct spread, usually from the lungs Histologically, there is disruption of the regular pattern
or pleura. Pathologically, typical caseating tubercles with of lipocytes with formation of lipid-filled spaces
discharging sinuses through the surface of the breast are surrounded by neutrophils, lymphocytes, plasma cells
found. ZN staining may demonstrate acid-fast bacilli. Fungal and histiocytes having foamy cytoplasm and frequent
infection of the breast may occur in immunocompromised foreign body giant cell formation. In late stage, there is
patients. replacement fibrosis and even calcification.
3. Silicone breast implants implanted on breast cancer patients
after mastectomy or as breast augmentation cosmetic surgery Galactocele
may rupture or silicone may slowly leak into surrounding A galactocele is cystic dilatation of one or more ducts
breast tissue. This incites chronic inflammatory reaction of occurring during lactation. The mammary duct is obstruc-
lymphocytes, macrophages and foreign body giant cells. ted and dilated to form a thin-walled cyst filled with milky
Eventually, a surrounding fibrous capsule forms and after a fluid. Rarely, the wall of galactocele may get secondarily
long period it may even be calcified.
infected.
4. Idiopathic granulomatous mastitis is an uncommon form of
reaction around lobules and ducts in the absence of any FIBROCYSTIC CHANGE
known etiology. Exact pathogenesis is not known but
probably it is a form of hypersensitivity reaction to luminal Fibrocystic change is the most common benign breast
secretion of the breast epithelium during lactation. condition producing vague ‘lumpy’ breast rather than