Breast Imaging Bullets

• Mucinous: Subtype of invasive ductal carcinoma. Dense mass on mammography. Isoechoic to fat on ultrasound. Slow growth with low tendency to metastasize.
• Tubular: Subtype of invasive ductal carcinoma with the best prognosis. Spiculated mass or architectural distortion on mammography. Hard to see on ultrasound, but may see architectural distortion in a single plane.
• Lobular neoplasia: New name for lobular carcinoma in situ. ~30% increased risk of cancer (ductal or lobular) in either breast.
• Roman arch: Micropapillary DCIS (low-grade DCIS).
• Granular cell tumor: Benign. Derived from Schwann cells.
• Occult cancers: By MRI, occult ipsilateral cancer in 15%-35% and occult contralateral cancer in 3% of newly diagnosed breast cancer patients.
• Radial scar: Excisional biopsy due to high incidence of associated proliferative changes with and without atypia, lobular neoplasia, and tubular carcinoma.
  
  
• Focal asymmetry on CC view: Roll views. Superior lesions move in the direction of the roll. Inferior lesions move in the direction opposite to that of the roll.
• Focal asymmetry on MLO view: Lateral view. Medial lesions move up on the lateral view compared to the MLO (Muffins rise). Lateral lesions move down on the lateral view compared to the MLO (Lead sinks).
  
  
• Shrinking breast: Infiltrating ductal carcinoma or diabetic mastopathy.
• Isolated unilateral axillary adenopathy: According to the BI-RADS FAQ: "In the absence of known infectious or inflammatory cause, isolated unilateral axillary adenopathy should receive a BI-RADS Category 4 assessment." Concern is for occult breast carcinoma or, much less commonly, metastatic melanoma, ovarian cancer, or other metastatic cancer. If a benign cause can be found (e.g., infection) BI-RADS Category 2 can be used.
• Isolated bilateral axillary adenopathy: According to the BI-RADS FAQ, in the face of known causes (lymphoma, HIV, sarcoid, systemic lupus erythematosis, psoriasis): BI-RADS Category 2. If no cause is known, then "it may be a sign of lymphoma and a BI-RADS Category 4 assessment is given. "
• Single dilated duct: Likelihood of being related to breast cancer is exceedingly low. BI-RADS-2 or 3. More recent data (not in the Holy BI-RADS) suggests that a solitary dilated duct "appears to have a greater than 2% likelihood of malignancy, sufficiently high to suggest that a suspicious (BI-RADS 4a) assessment may be appropriate."
• Multiple filling defects on ductography: BI-RADS 4a.
• Ductography: 30-G sialogram (blunt tipped) needle. ~1 cc barium (or until patient feels full).
• Complex mass on ultrasound: BI-RADS-4b
• Ultrasound-guided core biopsy: 14-G spring-loaded. 3-5 samples. Some places use 11-G.
• Stereotactic core biopsy: 11-G needle. 12 samples.
• Solid masses with increased through-transmission: Lymphoma and medullary carcinoma
• Male breast cancer: Ductal types (men don't have lobules)
• Architectural distortion: Invasive carcinoma (ductal, lobular), radial scar, biopsy scar.

References

• Chang CB, Lvoff NM, Leung JW, Brenner RJ, Joe BN, Tso HH, Sickles EA. Solitary dilated duct identified at mammography: outcomes analysis. AJR Am J Roentgenol. 2010 Feb;194(2):378-82.
• The American College of Radiology BI-RADS ATLAS and MQSA: Frequently Asked Questions.