22 - Breast Flashcards
Multifocal, bilateral blue-brown cysts (blue dome cysts) of the breast, measuring 1-5 cm diameter, filled with serous turbid fluid. Occurs normally in the menstrual cycle; histologically, cysts are lined with large and polygonal with abundant granular, eosinophilic cytoplasm and small, round, deeply chromatic nuclei (apocrine metaplasia); almost always benign.
Fibrocystic change
Defined as having more than two layers of lining epithelium (normally, one layer for luminal, and another for myoepithelial cells).
Epithelial hyperplasia
Type of fibrocystic change characterized by proliferation of luminal spaces (adenosis) lined by epithelial cells and myoepithelial cells with massive stromal fibrosis; important as it appears like carcinoma.
Sclerosing adenosis
Clinically presents with bloody or serous discharge; tumors usually are solitary and less than 1 cm in diameter, consisting of delicate, branching growths within a dilated duct; microscopically, composed of multiple papillae, each having a connective tissue core covered by double layer of epithelial cells (important distinguishing point from carcinoma counterpart).
Intraductal papilloma
These are stellate lesions characterized by a central nidus of entrapped glands in a hyalinized stroma; important as it appears like carcinoma
Complex sclerosing lesion/Radial scar
Basically, DCIS without full duct involvement; involves monomorphic proliferations of cells (vs. heterogeneous in epithelial hyperplasia).
Atypical ductal hyperplasia (ADH)
Basically, LCIS but <50% of acini in a lobule are involved; composed of monomorphic, loosely cohesive cells, with absence of E-cadherin.
Atypical lobular hyperplasia (ALH)
Most common location of breast carcinoma.
Upper outer quadrant (50%)
The two non-invasive breast carcinomas; both of which arise from terminal duct lobular unit (TDLU).
Ductal CIS (DCIS) and Lobular CIS (LCIS)
Immunostain to determine presence of myoepithelial layer; an important immunostain to distinguish in situ disease from infiltrating carcinomas.
p63
A distinct type of DCIS characterized by highly pleomorphic nuclei of cells (high-grade nuclei) with extensive central necrosis; with calcifications either from calcified necrotic debris or secretory material.
Comedocarcinoma
Clinically presents as an eczematoid lesion on the breast; associated with an invasive carcinoma in most cases; cause is an underlying DCIS that extended up to the lactiferous ducts and skin.
Paget disease of the nipple
CIS composed of monomorphic cells with bland round nuclei (low-grade nuclei) that occur in loosely cohesive clusters within the lobules; tend be more commonly bilateral.
LCIS
Most common of the infiltrating carcinomas; associated more with DCIS; characterized with intense desmoplasia that produces a hard palpable mass; microscopically, ranges from well-differentiated (tubule formation) to poorly differentiated (sheets of anaplastic cells); 50-65% are ER(+), HER2 (+) (luminal).
Invasive (ductal) carcinoma (No special type)
The system used in grading invasive carcinomas of no special type.
Nottingham system (Tubule formation, Nuclear grade, and Mitosis)
Infiltrating carcinoma with cells looking like those seen in LCIS; only in single-file conformation (Indian filing); reflecting loss of E-cadherin function, a molecule necessary for cohesion of breast epithelial cells; associated with adjacent LCIS in 2/3 of cases.
Invasive lobular carcinoma
Clinically presents as an enlarged, swollen, erythematous breast with a palpable mass; histologically high-grade; involves dermal lymphatic spaces, which explains the characteristic peau d’orange appearance; poor prognosis.
Inflammatory carcinoma
Infiltrating carcinoma composed of sheets large anaplastic cells, with increased mitosis, with well-circumscribed pushing borders with a pronounced lymphoplasmacytic infliltrate; increased incidence in patients with BRCA1 mutations; usually triple-negative breast cancer; poor prognosis.
Medullary carcinoma
The most common benign neoplasm of the female breast; grossly, discrete, usually solitary, freely movable nodule, 1 to 10 cm in diameter, easily shelled out lesion of the breast; histologically there is a loose fibroblastic stroma containing duct-like, spaces lined by a layer of epithelium that are regular and have a well-defined, intact basement membrane.
Fibroadenoma
Biphasic tumor composed of highly cellular stromal elements forming leaf-like projections and epithelial elements; usually benign and localized; ominous changes suggesting malignancy include increased stromal cellularity, anaplasia, high mitotic activity, rapid increase in size, and infiltrative margins.
Phyllodes tumor
Characterized by increase in connective tissue and epithelial hyperplasia of the ducts; lobule formation is rare.
Gynecomastia
Reason why male breast cancer tend to have less favorable prognosis than female breast cancer.
Less tissue for the tumor to invade in order to produce metastases
