TBL 1.2 Flashcards
What is the most common type of invasive breast cancer?
Ductal adenocarcinoma
How do invasive breast cancers typically present in the absence of mammographic screening?
As a mass of at least 2 to 3 cm in size
What factors influence the mammographic and gross appearance of invasive breast cancers?
The stromal reaction to the tumor
What is the typical appearance of invasive breast cancers on mammography?
A hard, irregular radiodense mass
What sound do tumors typically produce when cut or scraped?
A characteristic grating sound
What causes the characteristic grating sound in tumors?
Small, central pinpoint foci or streaks of chalky-white desmoplastic stroma and occasional foci of calcification
What can special tumors of breast cancer be organized into based on expression?
Molecular groups based on expression of ER and HER2
How do special histologic types of breast cancer differ from ductal carcinomas of no special type and break the established rules?
They often harbor unique genetic aberrations and distinct gene signatures and associations with clinical prognosis.
What is the subtype of breast cancer with the clearest association of phenotype and genotype?
Lobular carcinoma
What genetic alteration is commonly seen in lobular carcinoma?
Biallelic loss of expression of CDH1
How do lobular carcinomas typically infiltrate tissue?
As single cells
What is a characteristic feature of lobular carcinoma regarding desmoplastic response?
They sometimes fail to produce a desmoplastic response
What are the common sites of metastatic spread for lobular carcinoma?
Peritoneum, retroperitoneum, leptomeninges (carcinomatous meningitis) , gastrointestinal tract, ovaries, and uterus
What causes increased risk of lobular carcinoma in males and females?
Heterozygous germline mutations in CDH1
What is the association between lobular carcinoma and signet ring carcinoma of the stomach?
Individuals with CDH1 mutations have a greatly increased risk for signet ring carcinoma of the stomach
Why are carcinomas with a medullary pattern of interest?
Over half of BRCA1-associated carcinomas have this appearance
How does the prognosis of tumors with a medullary pattern compare to other poorly differentiated carcinomas?
Tumor with medullary tumor has a better prognosis
What unique feature related to T lymphocytes is noted in tumors with a medullary pattern?
They have an unusually large number of infiltrating T lymphocytes
What types of breast cancer almost always fall within the luminal group?
Luminal groups are ER-positive/HER2-negative cancers
Specific special histologic types
What are some of the special histologic types?
Lobular, mucinous, tubular and lobular carcinoma.
How can tumors present in the breast?
As well-circumscribed masses or almost imperceptible infiltrations
What is indicated by the presence of scant stromal reaction in tumor masses?
It suggests a well-circumscribed tumor
What can larger carcinomas invade?
The pectoralis muscle and the dermis
What physical change may occur in the skin due to tumor invasion of pectoralis and dermis?
Retraction or dimpling of the skin
What happens when the tumor involves the central portion of the breast?
Retraction of the nipple may develop
How can breast cancer rarely present before detection in the breast?
As metastasis to an axillary lymph node or a distant site
Why might a primary carcinoma be small and obscured?
Due to dense breast tissue or lack of desmoplastic response
How can “occult” primary tumors be detected?
By imaging studies using ultrasound or MRI
What scoring system is used for grading invasive carcinoma?
The Nottingham Histologic Score
What three factors are scored in the Nottingham Histologic Score?
Tubule formation, nuclear pleomorphism, and mitotic rate
What characterizes Grade I (well differentiated) carcinomas?
They grow in a tubular or cribriform pattern with small uniform nuclei
How do Grade 2 (moderately differentiated) carcinomas differ from Grade 1 carcinomas?
They have solid clusters or single infiltrating cells and greater nuclear pleomorphism and high number of mitotic figures
