Hippocrates named tuberculous lesions “pthisis” from the Greek word meaning “to decay”. Sir Astley Cooper was the first one who described a case of breast tuberculosis in 1829 and called it “scrofulous swelling of the bosom”. Later on, in 1952, McKeown an Wilkinson described two forms of breast tuberculosis, the primary in which breast infection is the only manifestation of the disease and the secondary one in which the patient had already tuberculosis diagnosed elsewhere.
Primary form is an infection of the breast through abrasions or through the openings of ducts in the nipple. Secondary form is the result of reverse lymph flow in the axillary lymph nodes or it may be due to direct spread of the infection from intra-thoracic foci. Routes of infection include:
1. Hematogenous spread.
2. Lymphatic spread from intra-thoracic foci or from an intra-abdominal foci.
3. Direct extension from adjacent tissues or via abrasions of the skin.
According to clinical, radiological and pathological appearance of the disease there are three types of breast tuberculosis:
1. Nodular tuberculosis which is characterized by a well-circumscribed, slowly growing, painless mass. Often the mass, getting larger, infiltrates the skin. At this point the tumor becomes painful, causing ulceration, and discharge from one or more sinus tracts. This course makes differentiation from carcinoma very difficult.
2. Diffuse type or disseminated tuberculous mastitis is characterized by multiple foci, which may lead to sinus formation. The overlying skin is thickened and painful ulcers may develop. Axillary lymph nodes are frequently infiltrated.
3. Sclerosing type, were excessive fibrosis is the dominant feature. It is slow-growing, and suppuration is rare. Clinically there is a hard, painless lump with nipple retraction.
Clinical examination usually fails to differentiate carcinoma from tuberculosis.
In mammography nodular tuberculosis reveals a dense, well-defined round or oval shadow, without the classic halo sign seen in fibroadenoma. Rarely infiltrating strands or skin thickening are present. Mammography is unreliable and differential diagnosis must be done from inflammatory or scirrous carcinoma. In the diffuse type breast is very dense, skin is thickened, painful and tense. Mammography shows a picture similar to that of an inflammatory carcinoma. In sclerosing type mammography reveals an homogeneous dense mass with fibrous septa and nipple retraction.
Ultrasonography is useful in characterizing the ill defined densities shown on mammography in order to confirm the presence of fluid and exclude the presence of a solid mass .
Magnetic Resonance Imaging (MRI) could be used in differentiation between scar granuloma and recurrence. Even with MRI, differentiation of a granuloma from an adenocarcinoma is difficult.
Fine needle aspiration cytology may reveal suppuration or characteristics of a granulomatous lesion. Open biopsy is the most reliable examination.
According to the literature an initial clinical diagnosis of breast tuberculosis is usually not made pre-operatively. This is because breast pain and mass are non-specific symptoms and imaging signs are unreliable. The most important inflammatory conditions encountered in the breast are:
1. Puerperal mastitis.
2. Non-pueperal mastitis which includes infected cyst, purulent mastitis with abscess formation and plasma cell mastitis.
3. Granulomatous mastitis which includes foreign body mastitis, specific diseases (as tuberculosis, sarcoidosis, syphylis, actinomycosis and typhus), parasitic diseases (as hydatid disease, cysticercosis, filariasis, schistosomiasis) and finally rare autoimmune diseases (as Wegener granulomatosis, giant cell arteritis, polyarteritis).