Breast Cancer: Anatomy, Pathology, Staging, and Management

Comprehensive vocabulary flashcards covering the epidemiology, clinical presentations, anatomical landmarks, lymphatic drainage, histology, molecular subtypes, and prognostic factors of breast cancer based on the lecture material.

The breast quadrant containing the greatest volume of glandular tissue and the most frequent site of primary breast carcinomas.

Upper Outer Quadrant (UOQ)

The anatomical quadrant of the breast where the occurrence of primary breast cancer is least common.

Lower Inner Quadrant (LIQ)

Posterior Nipple Line (PNL)

A radiographic reference line measured obliquely from the nipple back to the pectoral muscle or chest wall on a mammogram to verify adequate tissue visualization.

Rotter Nodes (Interpectoral Nodes)

Lymph nodes situated in the interpectoral space between the pectoralis major and pectoralis minor muscles.

Pathologic nodal risk correlated with primary tumor dimension: ___% <0.5cm, ___ for 0.6-1, ___ for 1-2, ___ for 2-5cm

5, 10, 25, 35%

The most common histologic subtype of breast malignancy ($80\%$ of cases), typically presenting as a firm mass with solid cords of cells accompanied by a prominent desmoplastic reaction.

Invasive Ductal Carcinoma (IDC)

A subtype accounting for $5\% \text{ to } 10\%$ of cases, characterized by a rubbery consistency, classic 'Indian filing' pattern of cells, lower visibility on mammography, high estrogen receptor positivity ($>80\%$), frequent multicentricity/bilaterality, and metastatic predilection for the meninges, serosal surfaces, bone marrow, ovaries, and retroperitoneum.

Invasive Lobular Carcinoma (ILC)

An aggressive, fast-growing subtype presenting with rapid erythema, warmth, breast enlargement, and peau d'orange, wherein widespread tumor emboli occlude dermal lymphatics; approximately one-third of patients have distant metastases at presentation.

Inflammatory Breast Cancer (IBC)

Carcinomas expressing estrogen receptors ($\text{ER}+$) and/or progesterone receptors ($\text{PR}+$), present in approximately ___% of breast cancer tumors

70

HER2-Positive Breast Cancer

Breast cancers characterized by amplification of the growth-promoting HER2 protein (present in $25\% \text{ to } 30\%$ of invasive cases), which grow rapidly but respond well to targeted anti-HER2 therapies.

Triple-Negative Breast Cancer (TNBC)

An aggressive breast tumor phenotype lacking estrogen receptors, progesterone receptors, and HER2 protein expression ($\text{ER}-/\text{PR}-/\text{HER2}-$), accounting for roughly $15\%$ of cases, more common in BRCA mutation carriers, and associated with limited targeted systemic therapy options.

strongest prognostic indicator for breast cancer

lymph node involvement

the breast overlies what muscle

pec major

the breast lies between which ribs

2 and 6

Approximately 30% of medial tumors and 15% of lateral tumors drain to the

IMN

WBI is indicated in most pts following

breast conservation surgery

whole breast irradiation dose

45 to 50.4 Gy in 1.8 to 2 Gy/fx, typically with a boost of
10 to 16 Gy.