behavior of neoplasms - lecture notes - julia Flashcards
note: i'm only putting in info we haven't already learned...there's a ton of stuff in this lecture that we learned several times cause it's all the basics of cancer...
<p>
| what is the difference between the new tissue formed during wound healing and during neoplasm development?</p>
<p>
wound healing tissue is carefully controled/carefully coordinated proliferation - have variety of cell types working together to restore the organism to normal physiologic function - requires postive and negative feedback loops - proliferation stops when defect is filled in</p>
<p>
in neoplasia - cells don't know when to stop dividing - not a normal process - growth doesnt serve a physiological process - cells don't necessarily respond to growth signals/feedback loops</p>
<p>
| what does it mean for neoplasms to be clonal? what is the evidence that they are clonal?</p>
<ul>
<li>
means that the mass derives from one cell that was mutated</li>
<li>
evidence = leiomyomas<br></br>
- leiomyomas are neoplasms of the smooth muscle of the uterus<br></br>
- can have multiple different lesions in one patient<br></br>
- researchers looked at the G6PD gene, which is on the x chromosome<br></br>
- because it's on the x chromosome, women are mosaic for it (50% of their cells will have allele A and the rest will have allele B)<br></br>
- all of the cells in an individual neoplasm will have the same allele types - but you can have two neoplasms with different alleles from each other (one with allele A in all of its cells and a second lesion with allele B in all of its cells)<br></br>
- this implies that each lesion arose from one individual cell (other wise you'd have a mix of the alleles in each neoplasm)<br></br>
- (note: the G6PD gene isn't assocated with the development of cancer - it's just a gene they were looking at)</li>
</ul>
<p>
| what is clonal progression? since mutations occur in all of us, why don't we all get cancer?</p>
<ul>
<li>
Key feature of neoplasia - there's no one mutation that leads to cancer</li>
<li>
Need accumulation of sequence of changes that impart to a cell or group of cells the ability to behave in a bad way/be malignant</li>
<li>
Get selective advantage to one cell – this begins to make more and more progeny – get another mutation – will get even more accelerated progeny</li>
<li>
This occurs at a measurable rate in all of us – but the mutations may be a mutation that targets cells for apoptosis or could be in an area that makes an antigen and NK cells will remove these cells – these are inherint mechanisms to prevent us from neoplasia</li>
<li>
how to prevent: don’t do things that increase rate of background mutation – ie don’t smoke, etc.</li>
</ul>
<p>
| what is/are the definition/characteristics of neoplasm?</p>
<p>
an abnormal proliferation of cells that arises from a single cell (clonal)</p>
<p>
due to stepwise genetic alterations that permit excessive growth that will exceed or be uncoordinated with normal tissues and will persist after growth signal has been removed</p>
<p>
| what are the differences in responses in cell signaling between neoplasm and normal cells?</p>
<p>
normal cells will stop growing when trophic factors are removed and will be inhibited from growing by contact with surrounding cells</p>
<p>
you need growth factors to make cells grow in culture</p>
<p>
neoplasm cells don't need any factors to grow - will grow regardless of the removal of growth factors, and don't respond to contact inhibition</p>
<p>
| what is the difference between hypertrophy and a neoplasm?</p>
<p>
hypertropy is an increase in cell size as a physiologic adaption response</p>
<p>
neoplasms are not in response to physiologic need</p>
<p>
in hypertrophy, if you take away the stimulus, it will stop growing and often reverse (think muscle if you stop working out)</p>
<p>
| what is the difference between hyperplasia and neoplasm?</p>
<p>
both involve an increase number of cells, but in hyperplasia this is an adaptive response to some stimuli that indicates to the body that the organ needs to enlarge, such as a goiter due to low iodine levels</p>
<p>
if you take the stimulus away froma hyperplasia, it will stop growing</p>
<p>
neoplasms aren't in response to a physiologic need and won't stop growing if signals are removed</p>
<p>
| how do metaplasias differ from neoplasms?</p>
<p>
a metaplasia is a change from one cell type to another as a protective mechanism - ie in Barrett's esophagus, you have growth of the mucus secreting epithelium into the esophagus in response to acid reflux since this tissue is better equiped to deal with acid than the squamous epithelium that lines the esophagus</p>
<p>
again, if you remove the stimulus, the abnormal growth will stop</p>
<p>
neoplasms are not in reponse to physiological need and won't stop growing when stimuli are removed</p>
<p>
| how do hamartomas differ from neoplasia? (and what are hamartomas?)</p>
<p>
hamartomas are growths of normal elements for a site/organ with an abnormal arrangement</p>
<p>
eg: can have a nodule of neural cells, such as astrocytes and neurons, in the meninges - it will be well circumscribed and will have no function - just sits there doing nothing - consists of normal tissue elements that are fully matured but it's in the wrong place, nonfunctional</p>
<p>
neoplasia is not normal, fully differentiated tissue usually</p>
<p>
| what is a popcorn calcification? what will it look like on xray and histologically?</p>
<ul> <li> pulmonary hamartoma</li> <li> called this because it looks like popcorn in the lung</li> <li> histologically will look like a mess of different cell types - all fully differentiated, but not the right kind of tissue for the area and not organized normally </li> </ul>
<p>
| what are the differences between benign and malignant neoplasms?</p>
<ul> <li> benign:<br /> - limited proliferation<br /> - no ability to invade<br /> - nodular<br /> - compresses tissue around it</li> <li> malignant<br /> - can invade and undergo metastasis<br /> - usually grows much faster</li> </ul>
<p>
| what is cancer?</p>
<p>
| malignant neoplasm - no such thing as a benign neoplasm</p>
<p>
| what is a carcinoma? where does it come from?</p>
<ul> <li> cancer that derives from surface coverings/glands</li> <li> can be derived from all three germ layers (endoderm, mesoderm, ectoderm)</li> <li> 80% of cancers </li> </ul>
<p>
| what is sarcoma? what are some examples and what tissue do these examples form from?</p>
<ul> <li> cancer from any tissue elements that aren't epithelial related</li> <li> mesenchymal</li> <li> examples<br /> - fibrosarcoma = fibroblasts<br /> - rhabdomyosarcoma = skeletal muscle<br /> - osteosarcoma = bone<br /> - chondrosarcoma = cartilage<br /> - liposarcoma = adipose tissue</li> </ul>
<p>
| how do cancer rates for men and women compare?</p>
<ul>
<li>
approaching parity (the same for both genders) except for in the sex tissues</li>
<li>
but frequency varies among tissue types</li>
</ul>
<p>
| what determines where primary tumors metasticize to? give some examples (gut, spleen, lungs, parenchymal, melanoma)</p>
<ul>
<li>
blood flow determines location of secondary tumor - will usually go to the first organ that gets most of the blood from the organ that had the primary tumor</li>
<li>
examples<br></br>
- blood from the gut and spleen go through the portal system into the liver so tumors from these organs like to migrate to the liver<br></br>
- with parenchymal tumors, blood first goes through the heart and then into the lungs so often get secondarly lung tumors</li>
<li>
some tumors have places they like to go best - not understood why, but there must be something in those tissues/vascular endothelial cells that attracts the tumor cells (concept of fertile ground)<br></br>
- melanoma likes to go to the brain<br></br>
- lung likes to go to liver and adrenals</li>
</ul>
<p>
| what is the TNM system?</p>
<ul> <li> used to evaluate stage of tumor</li> <li> gives number from 0 to IV</li> <li> more predictive than grade</li> <li> gives numerical value to tumor size, number of lymph nodes involved, and metasteses</li> <li> different scale/system for every organ</li> <li> see image for the system for the colon</li> </ul>
<p style="text-align:center;"> The nucleus indicated by the arrow best illustrates which malignant cytologic feature?</p> <ol> <li> Pleomorphism</li> <li> Differentiation</li> <li> Invasion</li> <li> Loss of polarity</li> <li> Hyperchromasia</li> </ol>
<p>
| 5</p>
<p style="text-align:center;"> The arrows indicate two populations of cells:They give evidence of…</p> <ol> <li> Benign & malignant</li> <li> Clonal progression</li> <li> Parenchyma & stroma</li> <li> Primary & metastasis</li> </ol>
<p>
| 2: clonal progression</p>
<p style="text-align:center;"> Which feature best characterizes the dysplastic epithelium in this actinic keratosis?</p> <ol> <li> Loss of polarity</li> <li> Invasion</li> <li> Anaplasia</li> <li> Angiogenesis</li> </ol> <p> (normal is on the left, dysplastic on the right)</p>
<p>
| 1</p>
<p> most likely diagnosis?</p> <ol> <li> Nevus</li> <li> Papilloma</li> <li> Adenoma</li> <li> Melanoma</li> <li> Lymphoma</li> </ol>
<p>
| 4</p>
<p> what abnormality accounts for the abnormal cel (big purple star thing in the middle)l?</p> <ol> <li> Loss of cell adhesion</li> <li> Loss of contact inhibition</li> <li> Escape from apoptosis</li> <li> Telomerase activity</li> <li> Extra centrosomes</li> </ol>
<p>
| 5</p>
<p> The cytologic feature that best defines this lesion as malignant?</p> <ol> <li> Abnormal mitotic figure</li> <li> High N:C ratio</li> <li> Pleomorphism</li> <li> Angiogenesis</li> <li> Necrosis</li> </ol>
<p>
| 3</p>
<p> Best diagnosis:</p> <ol> <li> Well differentiated SCC</li> <li> Poorly differentiated SCC</li> <li> Metaplasia</li> <li> Dysplasia</li> </ol>
<p>
| 1</p>
<p> This cancer has not yet acquired which malignant capability?</p> <ol> <li> Angiogenesis</li> <li> Invasion</li> <li> Growth factor independence</li> <li> Mitotic independence</li> </ol>
<p>
| 1</p>
<p> Best Answer</p> <ol> <li> Hyperplasia</li> <li> Hypertrophy</li> <li> Dysplasia</li> <li> Benign</li> <li> Malignant</li> </ol>
<p>
| 3</p>
