Cyto Flashcards
E2 Records: Retention of case materials
How long should the stained slides be kept in the lab?
How long should labs keep pateint’s specimen? processed and residual
How long should** images** retained? chromosome, FISH non neoplastic, FISH neoplastic
3 years
Processed: 2 weeks after the finals report is signed, residual: until release of final report
Chr and FISH non neo: 20 years, FISH neo: 10 years
E3.1 General analytical standards
Clone is defined as a cell population derived from a single progenitor cell. Clonal origin is inferred by the presence of at least……..cells containing the same extra chromosome(s) or structural chromosome abnormality or by the presence of at least …….. cells that have lost the same chromosome
Mosaicism is the presence of …….. cytogenetically distinguishable cell lines
two, three
two or more
E3.1 General analytical standards
What is the banding resolution goals in karyotypes?
peripheral blood studies: 550
amniotic fluid and chorionic villi cells: Minimum 400
E3.1 General analytical standards
For chromosome analysis how many cells should be counted, analyzed and karyotyped?
* Chronic Villi
* Amniotic fluid
* Blood
* POC/skin fibroblast
* BM/Leukemia blood/Solid tumor
E3.2 Abbreviated, Focused or Limited Chromosome Studies
In what situation abbreviated or limited cytogenetic study is appropriate?
- tissue confirmation of an abnormal prenatal chromosome result
- peripheral blood chromosome studies on extended family members to exclude an identified chromosome rearrangement
E3.3 Maternal Cell Contamination (MCC): Amniotic Fluid
- What is the overall frequency of MCC in amnio?
- What are the factors that increase the risk of MCC?
- What should be done with the first 1-2 ml of amnio?
- 0.5%
- gauge of needle, length of time in culture, presence of blood in the sample, first 1-2 ml of amnio drawn
- kept seperate from the rest of teh sample and used for cyto analysis if abseloutly necessary
E3.3 Maternal Cell Contamination (MCC): CVS
- What is the risk of MCC in CVS?
- How to reduce risk of MCC in CVS?
1-2% (higher than amnio)
A CVS specimen must be viewed under a dissecting microscope to allow for the gross identification
and cleaning of villi from maternal decidua, sterile instruments be used to tease apart the sample to
isolate the fetal chorionic villi from maternal decidua. Two laboratory technologists clean or check the dissected tissue prior to initiating cultures.
E3.3 Maternal Cell Contamination (MCC): POC
What is the main guidline for MCC in POC?
Due to the manner in which abortus tissue and placenta samples are obtained and handled, Consultation with the referring physician may be warranted to determine the origin of the sample and/or the appropriateness of chromosome studies, particularly in cases for which the dissection of tissue appears to yield only maternal decidua.
E3.3 Maternal Cell Contamination (MCC): Analysis with MCC
- What is the most likely explanation if XX found in an XY study? how should the full analysis and cell count be?
- What to do if prenatal studies?
- How to proceed if cell cultures initiated in the cytogenetics laboratory are to be used for molecular or biochemical testing?
- MCC, count and analysis should be on XY when possible, count and analysis for several XX needed for documentation purposes
- Further analysis to exclude chimerism, ultrasound to check the gender of fetus, second amnio or confirmatory on first amnio should be done
- any serious concerns about MCC in those cultures must be conveyed to the molecular or biochemical testing lab, if direct prenatal samples are sent out for testing, it is recommended that back-up cultures be grown and maintained until the molecular or biochemical testing is complete and reported.
E3.3 MCC Reporting and QA
- What are the recommendations for MCC reporting?
- Imagine a senario where MCC is suspected or confirmed, what should a lab director do?
- What are the recomendations for MCC monitoring?
- Consult physician who performed the procedure, if many normal female karyotype add a disclamer: MCC cannot be excluded
- Lab director must ensure that the cause is documented in QA documents
- Ratio of XX:XY should be monitored for QC check for CVS and POC cases, FISH with probes for X/Y or molecular methods may be used on cell suspensions prior to culturing to screen for or to estimate the amount of MCC.
E4.1 Amniotic fluid
What to do if no pellet in the amniotic fluid?
distinguish amniotic from other fluids using method (e.g., assays for pH, protein, glucose, etc.)
notification of inadequate or poor cell culture growth should be made within 10 days of the
amniocentesis procedure.
E4.1 Amniotic fluid
How many cells should be countes, analyzed and karyotyped in amniotic fluid sample?
E4.3 CVS
when mosaicisim documented,…..is recomended
Amnio
E4.4 Fetal blood
Final reports in the case of fetal blood testing (verbal or written) should be available within….. calendar days
7
