Differentials

Common

Fibroadenoma

History

asymptomatic, found incidentally, typical patient <40 years old

Exam

smooth, rubbery, mobile mass

1st investigation
  • mammogram:

    oval or round, circumscribed, may have coarse calcifications

  • breast ultrasound:

    solid, oval or round, circumscribed, lobulated, width greater than height

Other investigations
  • breast biopsy:

    epithelial and stromal elements

Fibrocystic breast

History

breast pain; commonly found in pre- and perimenopausal women; symptoms fluctuate with menstrual cycles

Exam

rubbery, well-circumscribed, mobile mass

1st investigation
  • breast ultrasound:

    simple cysts: well-circumscribed with sharp borders, no internal echoes; complex cysts: cystic and solid components

Other investigations
  • mammography:

    cannot distinguish between cystic and solid masses

  • breast aspiration:

    resolution of cysts after aspiration suggests a benign cyst

Fat necrosis

History

prior breast trauma, surgical reduction or augmentation

Exam

firm mass, irregular borders

1st investigation
  • breast ultrasound:

    indistinct margins, solid

    More
  • mammography:

    indistinct margins, sometimes with calcifications

    More
  • breast biopsy:

    fat necrosis

Other investigations

    Intraductal papilloma

    History

    bloody nipple discharge

    Exam

    mass usually small, not always palpable

    1st investigation
    • mammogram:

      may be negative

    • breast ultrasound:

      dilated duct with oval mass

    • breast ductogram:

      filling defect of duct

    Other investigations
    • breast biopsy:

      papillary growth pattern: benign papilloma, or atypia, papillary ductal carcinoma in situ, or invasive papillary carcinoma

    Breast abscess

    History

    breast pain, fever; alarming, rapid enlargement

    Exam

    breast fluctuance, tenderness, and skin erythema; associated mastitis

    1st investigation
    • breast ultrasound:

      fluid-filled cavity containing debris

    Other investigations
    • breast aspiration:

      purulent fluid

    Invasive breast cancer

    History

    gradual breast enlargement noted, personal or family history of breast cancer

    Exam

    hard, fixed mass; nipple inversion, nipple discharge, skin retraction, peau d'orange, lymphadenopathy

    1st investigation
    • mammogram:

      indistinct or spiculated margins, increased density, fine pleomorphic calcifications

    • breast ultrasound:

      irregular shape, ill-defined margins, height greater than width, punctate calcifications, hypoechogenicity

      More
    Other investigations
    • breast biopsy:

      cells with hyperchromatic nuclei invading into stroma

    Ductal carcinoma in situ (DCIS)

    History

    usually asymptomatic

    Exam

    breast mass may or may not be present; nipple discharge, breast tenderness, cracking of skin (Paget disease of breast)

    1st investigation
    • mammography:

      often associated with microcalcifications

    Other investigations
    • breast biopsy:

      malignant cells involving ducts that do not cross the basement membrane

    Uncommon

    Phyllodes tumor

    History

    40 to 60 years old; recent onset and rapid enlargement of breast

    Exam

    well-delineated, large breast mass

    1st investigation
    • mammography:

      oval, circumscribed mass

    • breast ultrasound:

      hypoechoic, well-circumscribed mass

    • breast biopsy:

      stromal and epithelial elements; histologic classification can vary from benign to malignant

      More
    Other investigations

      Adenoma

      History

      painless, slowly enlarging breast mass

      Exam

      well-circumscribed, mobile mass

      1st investigation
      • mammography:

        round or oval lesion with circumscribed margins

      Other investigations
      • breast ultrasound:

        solid, well-circumscribed mass

      • breast biopsy:

        tubular adenoma

      Atypical ductal hyperplasia (ADH) and atypical lobular hyperplasia (ALH)

      History

      usually found incidentally

      Exam

      rarely presents as palpable mass

      1st investigation
      • mammogram:

        no specific findings

      • ultrasound:

        no specific findings

      • breast biopsy:

        atypical cells

        More
      Other investigations

        Radial scar

        History

        usually found incidentally

        Exam

        rarely presents as palpable mass

        1st investigation
        • mammogram:

          no specific findings

        • ultrasound:

          no specific findings

        • breast biopsy:

          atypical cells

        Other investigations

          Lobular carcinoma in situ (LCIS)

          History

          usually found incidentally on breast biopsy for another purpose

          Exam

          rarely presents as a palpable mass

          1st investigation
          • mammogram:

            no specific findings

          • breast ultrasound:

            no specific findings

          • breast biopsy:

            malignant cells within lobular acini, basement membrane intact

            More
          Other investigations

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