how biopsies would you do confirm that something is a benign neoplasm?
options:
1. fine needle aspiration biopsy (FNAB): non-invasive, allows for preoperative planning and saves OR time
- core needle biopsy: guided with ultrasound
- excision of lump = lumpectomy
what are the microscopic features of a benign neoplasm?
- expansile growth rather than infiltrative
- well demarcated from surrounding tissue; smooth edges
- well differentiated = closely resembles normal tissue
- lacks malignant nuclear features
- not fixed to the tissue so it can move around
what is a fibroadenoma?
the most common benign solid breast lump in women from 15-30 years
what’s the treatment for fibroadenoma?
they’re benign
so most times treatment isn’t necessary but you have to follow-up to make sure there’s no changes in size or appearance
what are uterine leiomyomas?
aka fibroids
they’re the most common benign tumor of the uterus and originate from smooth cells of the myometrium
they can occur within the myometrium (intramural), just beneath the endometrium (submucosal), or beneath the serosa (subserosal)
what are submucosal leiomyomas?
benign uterine tumors just beneath the endometrium
they’re most often associated with abnormal bleeding from the expansile pressure of the tumor on the mucosal surface
what populations are associated with uterine leiomyomas?
most common neoplasm in females, specifically African American
smooth muscle cels of the myometrium respond to estrogens so most of these tumors arise during reproductive years –> they’re almost never found in prepubertal girls and post-menopause
is someone with a uterine leiomyoma at risk for uterine malignancy?
no
malignant transformation of leiomyomas is really rare
leiomyosarcomas are malignany smooth muscle tumors of the uterus and they’re rare neoplasm that arise de novo, unrelated to preexisting leiomyomas
what does desmoplasia mean?
refers to tumor-induced proliferation of non-neoplastic fibrous connective tissue
it’s commonly seen in adenocarcinomas of the breast, prostate and pancreas
break down the word “adenocarcinoma”
adeno = forming glands
carcinoma = arising from epithelial cells
how can you predict the consistency of a tumor based on the stroll appearance?
if there’s extensive collagen in the tumor, it’s consistency would be hard or scirrhous
what type of stain would you use for a breast tumor?
a marker for estrogen
if a tumor is positive for estrogen, this is a good prognostic sign and this can be exploited in treatment
antibodies are used to stain the tumor and the stain shows that basically all the tumor cells express estrogen receptor protein and they stain brown
how is estrogen receptor expression involved in the development of a breast tumor?
estrogen may bind to the receptors on the tumor cells and promote their growth!!
estrogen is not mutagenic so it’s a tumor promoter, NOT tumor initiator
in breast tumors that have estrogen receptors, how can this be exploited therapeutically?
since tumor cells can proliferate by binding estrogen, three therapeutic strategies are used to interrupt this process:
- interrupt the binding of estrogen to its receptor (tamoxifen)
- prevent estrogen production (aromatase inhibitors)
- deplete the supply of estrogen (oophorectomy) –> this is done a lot with patients who have BRCA1 or BRCA2 mutations
which drug interrupts the binding of estrogen to its receptor?
tamoxifen
which drug prevents estrogen production?
aromatase inhibitors
what depletes the supply of estrogen?
oophorectomy
how does immunohistochemical staining done?
it requires an antibody against the target protein to be detected
the antibody is conjugated to an enzyme that converts a colorless compound into a chromogen
this lets us visualize any antibody binding to the tissue
what are some characteristics of dysplasia cells?
- hyperchromic
- irregular nuclear outlines
- increased nuclear to cytoplasmic ratio
what is the difference between carcinoma in situ and invasive carcinoma?
CIS is confined to the epithelium and doesn’t go beyond the basement membrane
invasive carcinoma goes through the basement membrane into the underlying stroma
which virus is associated with cervical dysplasia?
HPV
high risk = HPV 16 & 18
low risk = HPV 31, 33 and 35
how can HPV lead to neoplasia?
the proteins encoded by the E6 and E7 genes high risk risk HPV disable important tumor suppressor proteins that regulate the cell cycle like p53 (E6) and RB (E7)
what is pleomorphism?
when the nuclei of a cell vary in size and shape
why is it important to know that a tumor has invaded into the muscle layer of the esophagus but not beyond it?
important in determining tumor stage!
staging of cancers is based on the size and extent of the primary lesion, the extend of spread to regional lymph nodes and the presence or absence of distant metastasis
staging is important to the clinician in determining the best course of therapy (more important than grading!)
what is grading?
tumor grading is based on the level of differentiation and the number of mitoses with the tumor
the grade of the cancer is presume to correlate with the neoplasm’s aggressiveness
what is metaplasia?
replacement of one mature epithelium with another mature epithelium in response to stress
what is Barrett’s esophagus?
patients usually have a history of heartburn or burning substernal chest pain especially after eating
there’s columnar metaplasia with goblet cells in the tissue samples
after many years, a dysplasia can arise in Barrett’s mucosa and from that an adenocarcinoma can arise
dysplasia in Barrett’s esophagus is regarded as the precursor of invasive malignancy
what environemal causes could lead to lung carcinoma?
smoking
what environmental cause could lead to mesothelioma?
asbestos
it’s a tumor of the tissue that lines the lungs, stomach, heart, and other organs
what environmental cause could lead to endometrial carcinoma?
estrogen
what environmental cause could lead to hepatic angiosarcoma?
vinyl chloride
what cancers could radiation exposure lead to?
bone cancer
leukemias
thyroid cancer
what happens to most people with a malignant neoplasm?
weight loss = cancer cachexia
if someone is gaining weight then it suggest a paraneoplastic syndrome!
the carcinoma could be secreting ACTH-like substances that is leading to increased glucocorticoid production and Cushing’s syndrome which would cause easy bruising, hypertension, glucose intolerance and truncal obesity
what are some characteristics of Cushing’s syndrome?
caused by the tumor secreting excess ACTH
ACTH hormone regulates steroid levels
characteristics = high BP, thin arms and legs but truncal obesity, moon face, red cheeks, buffalo hump, each bruising, red stretch marks, poor wound healing
how do sarcomas spread?
they tend to spread via the bloodstream
it’s less common that they spread via the lymphatic system