Breast cancer is the most common malignancy of women in the U.S. What type of this malignancy is most common? Describe the microscopic changes that take place.
- most common is invasive ductal carcinoma
- DC causes gland-like structures and solid nests of cuboidal cells to form
- In response to malignant tumor cells, there is a wide fibroblastic proliferation (desmoplasia -> a dense, collagenous stroma)
Patient presents with small mass in her breast and upon further investigation you find that it is an invasive ductal carcinoma. She wants to know about treatment options and her prognosis after surgery. What important characteristics of the tumor do you have to find out before you can give her a complete answer?
1) status of axillary lymph nodes : **most important prognostic factor! Sentinel lymph node is considered initial site of metastasis, and if this is involved the cancer is considered to have spread
2) estrogen receptor status : (+) hormone receptor status has a better prognosis than (-) status, and will also guide treatment as (+) tumors will be responsive to antiestrogens
- can also consider genetic mutations (BRCA, p53 etc), but these are less indicative of outcome
Gynecomastia associated with excess estrogens occurs in what 4 types of hormone balance issues?
- intake of exogenous estrogens
- presence of hormone-secreting adrenal or testicular tumors
- paraneoplastic production of gonadotropins
- metabolic disorders (liver, thyroid)
What are the findings of DCIS?
- no invasion of the BM
- noncomedocarcinoma - macropapillary, cribriform, or solid
- comedocarcinoma - necrosis and dystrophic calcification in the center of ducts
- Paget disease of breast - nipple ulceration and discharge due to cells extending up the nipple
- if left untreated, DCIS carries a 20-30% risk of becoming invasive over the next 20 years
Which holds a greater risk for development of breast cancer, fibrocystic changes in the breast or a family history?
- family history
What is a microscopic feature characteristic of invasive lobular carcinoma and what is the reason that these features form?
- grows in single file lines (or if we’re being super PC like Rubin’s, “Indian filing”)
- due to lack of E-cadherin
- this can help differentiate from invasive ductal carcinomas, which almost always gather to form duct-like structures
Buzzword bingo for types of invasive ductal carcinoma:
- medullary : sheets of highly pleomorphic/mitotic cells, lymphoid infiltrate with plasma cells
- mucinous/colloid : abundant jelly-like extracellular mucin
- tubular : tubules with no myoepithelial cells
- inflammatory : inflamed swollen breast (may be confused with mastitis), no discrete mass
If you get a question about male breast cancer, what is the most common type and what is the most common mutation you should be thinking about?
- invasive ductal carcinoma (invasion happens faster because there is less surrounding fat, but prognosis is similar to same stage in female) Also, males have few lobules because they don’t make milk