Breast Masses and Enlargement

Introduction

The evaluation of breast masses and enlargement is a high-yield topic for the MCCQE1. Breast complaints are among the most common reasons for primary care visits in Canada. While the majority of breast masses are benign, the primary objective in the Canadian medical context is to efficiently rule out malignancy while minimizing unnecessary anxiety and intervention.

Mastery of this topic requires understanding the “Triple Test” (Clinical assessment, Imaging, and Pathology) and applying age-specific differential diagnoses.

Clinical Approach: The Triple Test

The gold standard for evaluating a palpable breast mass in Canada is the Triple Assessment. When all three components are concordant, the diagnostic accuracy approaches 100%.

Differential Diagnosis by Age

For MCCQE1 preparation, categorizing differentials by age is the most effective strategy.

Specific Conditions and Management

1. Fibroadenoma

• Pathophysiology: Benign proliferation of stromal and epithelial elements.
• Presentation: Solitary, mobile, rubbery, non-tender mass.
• Management:
  • Ultrasound confirmation.
  • If typical appearance and <2-3 cm: Observation.
  • If growing or >3 cm: Consider biopsy/excision.

2. Fibrocystic Changes

• Pathophysiology: Exaggerated response to ovarian hormones.
• Presentation: Bilateral, multifocal pain/nodularity, worse pre-menses.
• Management: Reassurance, supportive bra, NSAIDs. Reduce caffeine (anecdotal evidence but often recommended).

3. Intraductal Papilloma

• Presentation: Unilateral, spontaneous, bloody or serous nipple discharge. Small subareolar tumor (often not palpable).
• Workup: Diagnostic mammogram + Ultrasound. Galactography (ductogram) may be used.
• Management: Surgical excision (duct excision) to rule out carcinoma.

4. Fat Necrosis

• Etiology: Trauma (history is key, though patient may not recall).
• Presentation: Can mimic carcinoma (firm, irregular, skin retraction).
• Diagnosis: Imaging may show oil cysts or calcifications. Biopsy often needed to confirm benign status.

5. Gynecomastia (Male Breast Enlargement)

• Definition: Benign proliferation of glandular tissue in males.
• Physiologic: Neonatal, Pubertal, Elderly.
• Pathologic:
  • Drugs (Spironolactone, Cimetidine, Digoxin, Marijuana).
  • Systemic (Cirrhosis, Hyperthyroidism, Renal failure).
  • Tumors (Testicular, Adrenal).
• MCCQE1 Tip: Differentiate from pseudogynecomastia (fat only) and male breast cancer (eccentric, hard, fixed).

Canadian Guidelines: Screening and Prevention

Understanding the Canadian Task Force on Preventive Health Care (CTFPHC) guidelines is essential for the MCCQE1.

Breast Cancer Screening (Average Risk)

Update Note: While some provinces (e.g., Ontario, BC) now allow self-referral at age 40, the CTFPHC (2018) guidelines emphasize shared decision-making for ages 40-49 rather than routine screening. Always prioritize national guidelines for MCCQE1 unless specified otherwise.

High-Risk Screening

For women with BRCA1/2 mutations or chest radiation history <30 years of age:

• Annual Mammography AND MRI.
• Typically starts at age 30 (or 25 for MRI in some protocols).

Investigation of Nipple Discharge

Key Points to Remember for MCCQE1

• The “Triple Test” is mandatory for any palpable mass.
• Age <30: Ultrasound is the first-line imaging modality.
• Age >30: Diagnostic Mammogram is usually the first step (often combined with US).
• Cyst Aspiration: If fluid is bloody or mass persists after aspiration $\rightarrow$ Biopsy.
• Inflammatory Breast Cancer: Suspect in “mastitis” that does not respond to antibiotics. It presents with rapid onset redness, edema (peau d’orange), and warmth.
• Paget’s Disease of the Nipple: Eczematous lesion on the nipple/areola. Associated with underlying DCIS or invasive cancer.
• BI-RADS 4 or 5: Requires tissue diagnosis (Core Biopsy).

Sample Question

Clinical Scenario

A 52-year-old woman presents to her family physician with a new, painless lump in her right breast that she noticed while showering one week ago. She has no personal or family history of breast cancer. Her last mammogram was 3 years ago and was normal. On physical examination, there is a 2 cm, firm, ill-defined, non-tender mass in the Upper Outer Quadrant of the right breast. There is no skin tethering or nipple discharge. No axillary lymphadenopathy is palpable.

Question

Which one of the following is the most appropriate next step in the management of this patient?

• A. Reassure the patient and repeat the clinical exam in 3 months
• B. Request a screening mammogram of bilateral breasts
• C. Request a diagnostic mammogram of the right breast
• D. Perform a Fine Needle Aspiration (FNA) in the office
• E. Refer immediately to a surgeon for excisional biopsy

Explanation

The correct answer is:

• C. Request a diagnostic mammogram of the right breast

Detailed Analysis

• Choice C is correct: In a 52-year-old woman with a new palpable mass, the first step in the “Triple Test” after the clinical exam is diagnostic imaging. Because she is over 30-35 years old, a diagnostic mammogram (often accompanied by a targeted ultrasound) is the standard of care in Canada. It evaluates the mass, checks for multicentricity, and assesses the contralateral breast.
• Choice A is incorrect: A new dominant mass in a post-menopausal woman is cancer until proven otherwise. Observation is dangerous and malpractice.
• Choice B is incorrect: A screening mammogram is for asymptomatic women. This patient has a symptom (a lump). She requires a diagnostic mammogram, which includes additional views (spot compression, magnification) and usually an ultrasound. Ordering a screening test may result in a delay or inadequate views.
• Choice D is incorrect: While tissue sampling is likely needed, imaging must precede biopsy. Imaging characterizes the mass and ensures the biopsy targets the most suspicious area. Furthermore, Core Needle Biopsy is generally preferred over FNA for breast masses in Canada to assess architecture and receptor status.
• Choice E is incorrect: Referral to a surgeon is appropriate after imaging results are available (unless the mass is obviously malignant and urgent referral is needed, but imaging is still required for surgical planning). The surgeon will need the imaging to plan the procedure.

References

1. Canadian Task Force on Preventive Health Care. (2018). Recommendations on screening for breast cancer. CTFPHC Website 
2. Medical Council of Canada. (2023). MCCQE Part I Objectives: Breast Lump. mcc.ca 
3. Cancer Care Ontario. Breast Cancer Screening Guidelines.
4. Sabel, M.S. (2023). Clinical presentation, diagnosis, and staging of breast cancer. UpToDate.
5. Toronto Notes 2023. General Surgery: Breast Surgery.