Case

• 29 y/o Korean female (nullipara) presents with a progressively enlarging right breast lump found on self-examination.

Case

• Not taking any medication.
• She was unmarried, but reported being with two sexual partners in the last year.
• She did not drink alcohol and had a smoking history of 5 pack years.

Case

• No significant past medical history, but a maternal aunt with breast cancer.

Case

• Vitals: 98.6 F. BP of 120/88. Pulse at 90 bpm. Respiratory rate of 20 breaths.
• General: Patient is awake, alert, oriented and responsive.
• HEENT: No JVD, no carotid bruits. No conjunctival pallor

Case

• Breast: 2.9 cm round mass in the upper-outer quadrant
• Heart: S1, S2 present. Regular rate. S3 gallop present, no thrills.
• Lungs: CTA-B. Bronchovesicular breath sounds.

Case

• Abdomen: Soft and non-tender abdomen, no guarding, no rigidity
• Extremities: No cyanosis or edema noted in extremities.
• Neuro: CN 2-12 intact. 2+ DTRs

Peters et. al

Case

• Estrogen receptor (ER)-positive, progesterone receptor (PR)-negative, human epidermal growth factor receptor 2 (HER-2)-positive.
• Adjuvant chemotherapy for 6 cycles followed by radiotherapy.
• Hormonal therapy with daily tamoxifen 20 mg, and trastuzumab

Epidemiology

• Second leading cause of mortality in women
• 1 in 8 women will develop breast cancer during their lifetime

NCI 2015

Key et. al.

Risk factors

Increased exposure to estrogen:

1. Obesity
2. Nulliparity
3. Early menarche (<11 y.o.)
4. Late menopause (>50 y.o.)
5. Late first pregnancy (>30 y.o.)

Risk factors

• Smoking
• Breast cancer in first degree relatives
• Atypical ductal hyperplasia

Risk factors

• BRCA1 and BRCA2 mutations
• Over-expression of ER/PR receptors
• Li-Fraumeni associated p53 loss

First Aid USMLE 2018​

Step-Up to USMLE Step 2 CK

Ductal Carcinoma in-situ

• Rises from progression of ductal hyperplasia
• Non-palpable mass on PE
• Seen on mammography due to microcalcifications

Bleiweiss et. al.

DCIS with central comedo-type necrosis.

First Aid USMLE 2018

Paget's disease

• Extension of DCIS into lactiferous ducts and skin of nipple
• Eczematous patches on nipple

Eczematous patches of Paget's disease

First Aid USMLE 2018

• Histology shows Paget cells: Large cells in epidermis with clear halo​

First Aid USMLE 2018

Lobular carcinoma in-situ

• Non-palpable mass
• No calcifications - Doesn't show on mamogram
• Completely incidental finding
• Often bilateral​

Histology shows distended lobules with neoplastic cells without BM penetration

First Aid USMLE 2018

Invasive lobular

• Often multiple lobes and bilateral
• Loss of e-cadherin - Responsible for forming cell clusters

Orderly lines

First Aid USMLE 2018

Inflammatory

• Poor prognosis (50% survival at 5 years)
• Dermal lymphatic invasion and blockage by tumor​

Peau d'orange

First Aid USMLE 2018