9 Laboratory Diagnosis of Neoplasia Flashcards
What are some examples of morphologic based tests?
cytology, histology, immunohistochemistry
what are the applications for serologic tumor markers?
screening, diagnosis, prognosis, and monitoring treatment response
T/F: Tumor markers are serologic markers that are only present in people with cancer.
F; tumor markers may be expressed in diseases other than cancer
What type of antigens are commonly used as serologic markers?
oncofetal antigens, expressed in fetal tissue but not typically in adults
what are the two best known serologic tumor markers?
CEA (carcinoembryonic antigen) and AFP (alpha-fetoprotein)
For what type of cancers is CEA the most widely used marker? what other types of cancers may it be used for?
Most widely used for gastrointestinal cancers, also used for some breast, liver, and lung cancers
Why isn’t CEA used for screening in asymptomatic patients?
It has low positive predictive value and has limited value in screening asymptomatic patients.
Why is CEA used to follow patients in whom it was elevated pre-operatively?
rising postoperative levels can be evidence of recurrence
What other condition can lead to an elevation in CEA, and could therefore create a false positive?
elevations in serum CEA may be due to liver disease
T/F: highly elevated CEA prior to surgery may be associated with metastases and a worse prognosis
T
Where is AFP synthesized in the embryo and fetus?
yolk sac and hepatocytes
What is AFP most useful in diagnosing when elevated in adults?
hepatocellular carcinoma and germ cell tumors that have yolk sac like differentiation (endodermal sinus tumor in the ovary and yolk sac tumor in the testes)
In what cancers is CA 125 elevated?
CA 125 is high in >75% of epithelial ovarian carcinomas, and can also be elevated in benign and malignant uterine tumors.
T/F: A decline in CA 125 during treatment of ovarian carcinoma means the cancer is being successfully treated.
F; CA 125 can show a false decline during therapy of ovarian carcinoma.
In what cancers is CA 19-9 elevated?
pancreatic, colorectal carcinoma, and gastric carcinoma
T/F: CA 19-9 is related to Lewis blood group substances.
T
Where is PSA produced? What is it used to screen for?
produced in the epithelial cells of the prostate gland; it is used to screen for prostate carcinoma and is also used in post surgical followup
Which is greater, the sensitivity or specificity of PSA as a screen for prostate carcinoma? why?
The sensitivity is better. PSA may also be elevated in infection, hyperplasia, or other benign processes.
what are normal levels of PSA in the blood?
0-4 ng/ml
what does a detectable level of PSA following a total prostatectomy indicate?
Metastasis or recurrence
name the 5 major categories of malignancy
carcinoma, hematopoietic neoplasia, sarcoma, melanoma, and neuroepithelial
What is a malignancy of epithelial-derived tissues called?
carcinoma
Breast, colon, lung, and ovary cancers are usually what type of malignancy?
carcinomas
What is a malignancy of blood element-derived tissues called?
hematopoietic neoplasia
What is a malignancy of mesenchymal tissues called? what are mesenchymal tissues?
sarcoma; bone, muscle, vessels
What is a malignancy of CNS or PNS tissues called?
neuroepithelial tissues
What is cytology?
a morphologic based test that relies on individual cells or small clusters of cells with little or no reliance on the microscopic architecture of the lesion
T/F: Nuclear:cytoplasmic ratio is decreased in malignancy
F, it is increased
Are body fluids examined using exfoliative or aspiration cytology?
exfoliative
what type of cytology is a pap smear (exfoliative or aspiration)?
exfoliative
T/F: FNA of deep-seated lesions can be performed using CT or ultrasound guidance
T
What are some of the drawbacks of using cytology in diagnosis of malignancies?
1) Some malignancies cannot be conclusively diagnosed with cytology
2) cytology cannot give a complete prognosis
3) it cannot determine the extent of the carcinoma in some situations
What are some of the histologic features of adenocarcinomas?
cohesive cells that form glands
What are some of the histologic features of squamous carcinomas?
cohesive cells with intercellular bridges and keratinization
What are some of the general histologic features of hematopoietic tumors?
discohesive cells with no intercellular bridges or gland formation
What are some of the histologic features of leukemias?
may have cell features of immature myeloid cells of marrow, all of one type and stage of maturation
What are some of the histologic features of sarcomas?
often have spindle cells, and often cohesive without intracellular bridges
what is a smooth muscle malignancy called?
leiomyosarcoma
what is a myofibroblast malignancy called?
fibrosarcoma
what is a peripheral nerve malignancy called?
neurofibrosarcoma
what is a skeletal muscle malignancy called?
rhabdomyosarcoma
what type of malignancy is pigmented and contains a mixed cellular appearance with large epithelioid cells and bizarre nuclei?
melanoma
what is immunohistochemistry?
a technique that allows use of specific antibodies to be reacted on tissue slides to identify markers of interest
T/F: immunohistochemistry alone is insufficient for diagnosis of a malignancy.
T, must be used in conjunction with histology or cytology
what are some of the major uses of immunohistochemistry?
1) Categorization of tumors
2) Classification of malignant neoplasms, particularly lymphoma
3) Determination of origin of metastatic tumors
4) Detection of molecules for therapeutic significance
