• Proliferative benign breast lesions wo atypica

  • Usual ductal hyperplasia

  • Intraductal papilloma

  • Radial scar/complex sclerosing lesion

  • Sclerosing adenosis

  • Fibroadenomas

  • Adenomas

  • PASH

• Excessive growth of benign cells in the breast

  • Cells are normal in appearance.

• Location:

  • Inner lining of the breast duct

  • Lobule

• Risk:

  • Mild UDH - no increased risk

  • Moderate to florid UDH - increased risk of breast CA (1.5-2x normal)

• Tx: none

• Consist of papillary cells that grow from the wall of a duct into its lumen

• Features:

  • 70-90% of sx IP occur in the subareolar breast with main duct/lactiferous sinus

  • Most common cause of bloody nipple discharge.

  • Usually solitary, in large ducts, and may be intracystic (inside a dilated duct)

  • There is usually some fluid evident surrounding at least a portion of a solid mass on sonography

  • Most present with nipple discharge; usually clear but can be bloody

    • Suspicious discharge: unilateral spontaneous, uniductal clear or bloody nipple discharge

    • If US and mammography are unrevealing for suspicious nipple discharge, further evaluation with galactography or MR should be considered.

• Types:

  • Solitary IP - benign and MC

  • Multiple IP aka Diffuse Papillomatosis

    • Increased breast CA risk slightly

    • Some studies suggest MRI to evaluate for enhancement.

• Traditional tx is surgical excision due to possibility of upgrade

  • 15-20% risk of upgrade to carcinoma or high-risk lesion (atypical ductal hyperplasia)

  • Less change of upgrade with smaller size (<1 cm)

  • There is some evidence for more conservative approach if asx

• Radial scar <1 cm and CSL >1 cm

• Benign hyperplastic proliferation

  • ?2/2 local inflammation or chronic ischemia leading to slow infarct

• Increasing incidence

  • 0.1-2 per 1000 screens

  • Likely 2/2 DBT screening

• Upstaging to DCIS or invasive carcinoma is greater when lesion is >1 cm.

  • 8-17% upgrade rate; increased chance if atypica is present.

• Considered a high-risk lesion and requires surgical excision.

• Expanded lobules w/ an increased number of acini/ductules

  • Reflects the sclerosing or hardening of these acini

  • Histo may be found at bx of amorphous calcs or incidentally and is often admixed w/ other proliferative changes

• Enlarged breast lobules are distorted by scar-like tissue/stromal fibrosis

• Assoc w h/o cyclical breast pain.

• Benign

• No treatment required

• Not premalignant but associated w/ an increased CA risk of 1.5 - 2 x

• Not high-risk finding and is considered benign unless the imaging features of the bx target warrant a "discordant" assessment (linear/branching calcs or a spiculated mass).

• MC benign tumor of the breast

• Hormone responsive solid tumor containing glandular and fibrous tissue

  • Increase in size during reproductive years, pregnancy, estrogen therapy

  • Regress after menopause

• Can be multiple or bilateral (20%)

• Management (bx proven)

  • Simple - not necessary to excise

  • Complex - surgical excision or FU imaging.

• FU

  • 2 years of imaging FU (6 mo, 12 mo, 24 mo)

  • If >20% growth is observed during the FU period, bx should be performed.

  • Women with FA > 3 cm are sent for surgical consultation

Giant fibroadenoma

• >5 cm

• Found in lactating and pregnant women

• Can be found in juvenile girls (juvenile fibroadenoma)

• Rapidly growing

• 0.5 - 2% of all FAs

• Benign; Do not undergo malignant transformation

• Uncommon fibroepithelial tumors

  • <1% of all breast neoplasms

  • A form of sarcoma

  • On imaging can be indistinguishable from FA

• "leaf-like" describes the typical papillary projections that are seen on pathologic examination.

• Median age at presentation 42-45 yo

• Assoc w Li-Fraumeni syndrome

• Suspect anytime a patient presents with a large (>3 cm), rapidly growing, palpable mass.

• Tx

  • Complete surgical excision

    • High recurrence rates if close margins (>1 cm desired)

  • Radiation therapy

    • For borderline and malignant phyllodes only

  • Chemotherapy

    • For distant metastatic dz (seen in 13-40% of patients, lungs)

    • Hormonal therapy is not effective

• Pure epithelial neoplasms w/ sparse stromal elements unlike FA

• 2 types

  • Tubular adenomas

    • Rare and seen in young premenopausal women

    • Radiologic / cytologic features are not specific thus requiring excision for final diagnosis

  • Lactating adenomas

    • Occurs during pregnancy

    • Well circumscribed and lobulated

    • No malignant potential

• Benign proliferation that simulates a vascular lesion histologically

• Presents as a mass or thickening on clinical exam

• Solid well-defined noncalcified mass on imaging

• If suspicious features on imaging and bx shows PASH, surgical excision is warranted.

  • If concordant with imaging, there is no increased risk of breast CA assoc w PASH

FIBROMATOSIS

• Locally aggressive proliferation of fibroblasts and myofibroblasts (AKA extrabdominal desmoid)

• Usually arises from the pectoralis fascia

• Presents as a painless, palpable firm irregular mass usually arising from the pectoralis fascia

• Wide local excision is standard.

• Local recurrence rates are 21-27% (usually w/n 3 years)

• No metastatic potential