Benign Breast Lesions and Clinical Presentations

Benign Breast Lesions

• Pathology of Benign Breast Lesions: Includes various types of cysts (Type I & II), papilloma, ductal hyperplasia, sclerosing adenosis, fibrocystic, and fibroadenoma. Visual aids (images) show examples of each.

Clinical Presentations of Breast Disease

• Pain (Mastalgia): 95% of cases are benign.
• Mass >2cm: Can be a cyst, fibroadenoma, or carcinoma.
• Nipple Discharge: Can be bloody/serous (cyst, intraductal papilloma), or milky (galactorrhea, pituitary adenoma, hypothyroidism, anovulation).

Non-Neoplastic Breast Lesions

• Inflammation: Includes mastitis (acute and chronic forms). Chronic mastitis further breaks down to granulomatous, periductal, and plasma cell mastitis.
• Galactocele: Obstructed mammary ducts resulting in a cyst filled with milky fluid, potentially secondary infection.
• Fat Necrosis: Painless mass, skin thickening, or nipple retraction, mammographic density or calcifications are possible. Results from trauma or surgical procedures.
• Benign Epithelial Lesions: Categorized as non-proliferative (fibrocystic changes), proliferative (without atypia-fibroadenosis, etc.), and proliferative (with atypia, a higher risk of developing cancer).

Mastitis

• Acute Mastitis: Acute pyogenic infection, common in the first few weeks of breastfeeding (lactation). Mode of spread is often via nipple fissures.
• Chronic Mastitis: Includes granulomatous, periductal, and plasma cell mastitis.
  • Granulomatous mastitis: Linked to systemic diseases (sarcoidosis), foreign bodies (silicone implants), or infections (TB or fungi).
  • Periductal mastitis: Smoking is a significant risk factor. Characterized by painful subareolar masses, duct dilation, rupture, and chronic/granulomatous inflammation.
  • Plasma cell mastitis (mammary duct ectasia): NOT associated with smoking; it affects perimenopausal/multiparous women (ages 50-70). Symptoms include a painless mass, nipple discharge, and sometimes a lump.

Mammary Duct Ectasia (Plasma Cell Mastitis)

• Characteristics: Peri-areolar location; no association with smoking; usually affects multiparous women (50-70 years). Symptoms include a poorly defined painless mass, white nipple discharge, and thick, viscus nipple secretions.

Fat Necrosis

• Clinical Presentation: Painless mass, skin thickening, possible nipple retraction, mammographic density or calcification, linked to trauma/surgery
• Histology: Hemorrhage and acute inflammation, leading to fat necrosis, followed by chronic inflammation with giant cells/hemosiderin and scar tissue, often with dystrophic calcification.

Galactocele

• Risk Factor: Lactation
• Pathogenesis: Obstruction and dilation of mammary ducts, forming a thin-walled cyst filled with milky fluid. Possible secondary infection

Benign Epithelial Lesions

• Fibrocystic Changes: Increased numbers of acini per lobule, with cystic and fibrous tissues often leading to a lumpy breast appearance. May include cysts with flat or apocrine metaplasia, fibrosis (ruptured cyst), and calcification.
• Proliferative without Atypia: Includes sclerosing adenosis (increased acini per lobule), papillomas (epithelial growth with fibrovascular core, often causing nipple discharge), and complex sclerosing lesions (sclerosing adenosis + papillomas). Epithelial hyperplasia (layers of cells) is key, as are normal cytology and architecture.
• Proliferative with Atypia: Atypical ductal hyperplasia (ADH) and atypical lobular hyperplasia (ALH) resemble carcinoma in situ, but are monomorphic (similar-looking) and lack atypical characteristics.

Benign Breast Tumors

• Stromal Origin: Fibroadenoma, Phyllodes (tumor origin from connective tissue)
• Epithelial Origin: Duct papilloma (benign tumor in the milk ducts)

Fibroadenoma

• Description: A common benign breast tumor most common in women ages 15–30 during their reproductive years, characterized by a solitary, mobile, well-encapsulated nodule.
• Histology: Circumscribed borders, low cellularity, and rare mitoses. Intracanalicular or pericanalicular patterns of fibrous overgrowth (and ducts).

Phyllodes Tumor

• Description: Uncommon, potentially aggressive breast tumor seen in women 30–70.
• Gross Anatomy: Usually large (10–15 cm), round/oval, bosselated, with possible cystic areas, hemorrhages, necrosis, and degenerative changes.
• Histology: Increased connective tissue (stromal) overgrowth with proliferating stromal cells covered by epithelium.
• Behavior: Can range from benign to borderline to malignant; mitoses, atypia, cellularity, and infiltrative margins may highlight the aggressive nature of the tumor.

Intraductal Papilloma

• Description: Benign papillary tumor usually found near the nipple in milk duct areas.
• Clinical Presentation: Serous or serosanguinous nipple discharge is a common symptom.
• Gross Anatomy: Typically solitary, small (less than 1 cm).
• Histology: Multiple papillae with well-developed fibrovascular stalks. Benign cuboidal epithelial cells supported by myoepithelial cells.

Explore the pathology and clinical presentations of benign breast lesions through this quiz. Learn about various types of cysts, fibroadenomas, and the impact of conditions like mastalgia. Visual aids and descriptions will enhance your understanding of non-neoplastic breast lesions.