• Nonproliferative benign breast lesions

  • Simple cysts

  • Galactoceles

  • Papillary apocrine changes

• Presents mammographically as dense breasts with scattered punctate calcifications and fluctuating cysts that may or may not contain milk of calcium. 

• Cysts are not dense are only rarely calcify

• Papillary apocrine changes aka apocrine metaplasia are changes that occur 2/2 irritation

• Benign morphological change of the TDLU epithelium to secretory epithelium with associated acinar dilatation

  • Detected on US as clustered microcysts if they become large enough.

• Apocrine-like cells form in a linking of developing microcysts 2/2 increased intraluminal pressure

• Common finding in the breast; incidence as high as 85% at autopsy

• Associated with fibrocystic changes

• Cluster of small cysts (aka microcysts, 2-5 mm) with intervening septae

• BR 2 - benign

• RISK

  • No associated risk of upgrade to malignancy at excision

  • There is an increased risk of developing CA when hyperplasia is seen along with metaplasia 

• Tx:

  • If imaging is concordant, no further tx is needed.

PHYLLODES TUMOR

• Can present as complex cystic and solid mass

• 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

• DCIS can also present as an intraductal mass however it is much less likely to present as an intraductal solid mass than IP.

  • Blood nipple discharge merits further evaluation; 13% are 2/2 malignancy (typically DCIS)

  • Spontaneous clear nipple discharge is much less often malignant.

LIPOMA

• AKA fibroadenolipoma

• More encapsulated appearance with both fat and glandular elements within.

• Has a breast within a breast mammographic appearance and would not have peripheral calcifications.

• Mammographic diagnosis! It is difficult to demonstrate on US as they blend in with surrounding tissue.