Breast Masses and Enlargement

Welcome to our comprehensive MCCQE1 study guide on breast masses and enlargement. This article is tailored for Canadian medical students preparing for the Medical Council of Canada Qualifying Examination Part I (MCCQE1). We'll cover key concepts, Canadian guidelines, and provide practice questions to help you succeed in your exam.

Introduction to Breast Masses and Enlargement

Breast masses and enlargement are common presentations in Canadian primary care and surgical settings. Understanding their evaluation and management is crucial for MCCQE1 success and future medical practice in Canada.

Types of Breast Masses

Breast masses can be broadly categorized into benign and malignant lesions. Here's a comparison table of common breast masses:

Evaluation of Breast Masses

The Canadian approach to evaluating breast masses follows a systematic process:

Canadian Guidelines for Breast Cancer Screening

The Canadian Task Force on Preventive Health Care recommends:

• Women aged 50-74: Mammography every 2-3 years
• Women aged 40-49: Individual decision based on patient values and risk factors
• No routine clinical breast examination or breast self-examination

Management of Breast Masses

Management depends on the nature of the mass:

Key Points to Remember for MCCQE1

1. 🔑 Triple assessment is crucial: clinical examination, imaging, and tissue sampling
2. 🔑 Canadian screening guidelines differ from other countries
3. 🔑 Age is a key factor in determining the appropriate imaging modality
4. 🔑 Most breast masses in young women are benign
5. 🔑 Any new breast mass in a postmenopausal woman should be considered malignant until proven otherwise

MCCQE1 Mnemonic: BREAST

• Benign vs. malignant characteristics
• Risk factors assessment
• Examination (clinical and imaging)
• Age-appropriate screening
• Sampling (FNA or core biopsy)
• Treatment based on diagnosis

Sample Question

# Sample Question

A 55-year-old woman presents with a newly discovered right breast lump. She has no family history of breast cancer and is postmenopausal. On examination, you palpate a 2 cm firm, irregular mass in the upper outer quadrant of the right breast. There is no skin dimpling or nipple retraction. Which one of the following is the most appropriate next step in management?

- [ ] A. Reassure the patient and follow up in 6 months
- [ ] B. Perform fine-needle aspiration of the mass
- [ ] C. Order breast ultrasound
- [ ] D. Refer for mammography and ultrasound
- [ ] E. Prescribe antibiotics for suspected mastitis

Explanation

The correct answer is:

• D. Refer for mammography and ultrasound

Explanation: In a postmenopausal woman with a newly discovered breast mass, the most appropriate next step is to refer for imaging studies, specifically mammography and ultrasound. This follows the Canadian approach to breast mass evaluation, which emphasizes a thorough workup for any new breast mass in postmenopausal women due to the increased risk of malignancy in this age group.

Mammography is the primary screening tool for women over 50 in Canada, and when combined with ultrasound, it provides a comprehensive evaluation of the breast tissue. This approach aligns with the triple assessment method (clinical examination, imaging, and tissue sampling) recommended for breast mass evaluation.

Options A and E are incorrect as they delay proper evaluation of a potentially malignant mass. Option B (fine-needle aspiration) is premature without imaging studies. Option C (ultrasound alone) is insufficient for a postmenopausal woman, as mammography is the primary imaging modality for this age group in Canada.

Canadian Guidelines

The Canadian Association of Radiologists (CAR) provides guidelines for breast imaging:

1. Mammography is the primary screening tool for average-risk women aged 50-74
2. Ultrasound is used as a supplementary tool, especially in dense breasts
3. MRI is recommended for high-risk women (e.g., BRCA1/2 mutation carriers)

References

1. Canadian Task Force on Preventive Health Care. Recommendations on screening for breast cancer in average-risk women aged 40–74 years. CMAJ. 2018;190(49):E1441-E1451. Link (opens in a new tab)

2. Canadian Association of Radiologists. CAR Practice Guidelines and Technical Standards for Breast Imaging and Intervention. Link (opens in a new tab)

3. Breast Cancer Society of Canada. Breast Cancer Screening Guidelines. Link (opens in a new tab)

4. Cancer Care Ontario. Ontario Breast Screening Program (OBSP) Guidelines Summary. Link (opens in a new tab)

5. Canadian Cancer Society. Breast cancer statistics. Link (opens in a new tab)