Lactational mastitis

Forms and classification of mastitis

Mastitis is an inflammatory disease of the breast that can have either an infectious (caused by pyogenic bacteria) or non-infectious (including viral) etiology.

Based on the relationship with milk production, two main groups are distinguished:

• Lactational (postpartum) mastitis — the most common pathology associated with lactation in the postpartum period.
• Non-lactational mastitis — occurs in non-pregnant women, as well as in men and children.

There are also specific, rare forms of inflammation. These include idiopathic granulomatous mastitis (a benign condition of unknown etiology) and tuberculous mastitis, which is an extrapulmonary form of tuberculosis infection affecting the tissue of one or both mammary glands.

Stages of progression of lactational mastitis

The clinical classification of lactational mastitis is based on the sequential progression of the inflammatory process. The disease goes through the following stages:

1. Serous — the initial stage of inflammation.
2. Infiltrative — formation of induration in the glandular tissue.
3. Purulent — development of purulent melting.
4. Infiltrative-purulent.
5. Abscessing.
6. Phlegmonous.
7. Gangrenous — the most severe stage with tissue necrosis.

Associated conditions and complications

The development of mastitis is often promoted by functional disorders. Hypergalactia is characterized by excessively abundant milk secretion, while lactostasis is a dysfunctional condition with delayed milk outflow.

If inflammation progresses, localized purulent foci may form:

• Breast abscess — a localized inflammatory focus within the soft tissues, representing an encapsulated cavity containing pus.
• Subareolar abscess — a purulent cavity localized directly in the areolar region (often a complication of periductal mastitis).
• Periareolar fistula — a pathological tract connecting the inflammatory focus to the skin.

Inflammation of nipple and duct structures

The pathological process may involve individual anatomical elements of the breast. Defects in skin integrity are designated as nipple fissures. Isolated inflammation of the periareolar region is termed areolitis, and inflammation of the nipple itself is called theliitis.

Inflammation of the mammary ducts is classified separately:

• Intraductal mastitis (galactophoritis) — the inflammatory process is localized within the duct.
• Periductal mastitis — disease of the subareolar ducts.

Also distinguished is duct ectasia, which is a separate nosological form and can lead to the development of chronic inflammation known as retention mastitis.

Differential diagnosis: mastopathy

In addition to inflammatory diseases, the breast is susceptible to dyshormonal changes, such as benign dysplasia (mastopathy). The disease may be asymptomatic or present with the characteristic clinical triad: mastalgia (pain), the presence of indurations in the glandular tissue, and pathological nipple discharge.

Two main forms of mastopathy are distinguished:

• Diffuse — changes are widespread throughout the entire breast. It may occur with a predominance of glandular (adenosis), fibrous, cystic components, or be mixed.
• Nodular — characterized by the formation of local lesions (cysts, areas of local fibrosis, focal fibroadenomatosis). These indurations are palpable as discrete nodes and always require careful differential diagnosis with a neoplastic process.

Class and exam questions

What else to study on this topic

• Clinical and morphological features of benign dysplasia (mastopathy)
• Morphology and clinical presentation of mammary duct ectasia
• Differential diagnosis of nodular mastopathy and malignant neoplasms
• Pathogenesis and etiology of idiopathic granulomatous mastitis

Other topics in the "Additional Topics" section

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.