(From Dr. Coutino and Dr. Tweeddale, 2000, by Brian Buschman)
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Parenchyma is a whole bunch of growing cells. The related supporting structures like blood vessels and CT are known as the stroma. Any parenchyma needs a stroma.
-Oma is the suffix that is used to identify a tumor of a tissue. Usually –omas are benign but there are exceptions like malignant melanoma.
Sarcomas are malignant –omas related to proliferation of mesoderm usually from fibroblastic proliferation.
Carcinomas are –omas of epithelial cells like cell carcinomas. Technically it is a tumor of ectoderm or endoderm.
Carcinosarcomas are tumors that possess properties of both sarcomas and carcinomas. The tumor spans and includes tissues from more then one cell layer.
09829 – Tumors can be well, moderately or poorly differentiated. This slide shows a squamous cell carcinoma. This cell is making keratin so it must be a completely unique cell and hence it is well differentiated.
1) Nuclear pleomorphism means that some cells have a nucleus that is much bigger or shaped differently then those of other cells.
2) Nuclear hyperchromasia. When you stain the nucleus it turns dark because the die is picked up by the DNA. Since malignant cells are dividing too quickly they have excess DNA and stain darker then other cells.
3) Atypical mitotic figures are seen. They are odd but still have the characteristics of mitotic figures.
4) Large nucleoli exist to hold the excess DNA.
5) Disorganized size and organization of the cells.
6) Necrosis – The proliferation of the malignant tissues can lead the neoplasm to overgrow it’s vascular supply hence it undergoes necrosis.
7) Metastasis is part of what defines malignancy.
Tumors can spread by three main routes:
1) Hematogenous spread involves spread via blood.
2) Lymphatic spread is via lymphatics.
3) Direct extension is when a tumor spreads by a direct body cavity/pathway. Examples include spread through peritoneal areas or in the CSF.
39731 – Ovarian cancer that metastasized to the bowel. It spreads by direct extension by seeding the peritoneum.
41371 – Metastasis in the lungs is almost originating from another organ. Because of the lung’s position in the circulatory system the lungs are sites of metastasis of many tumors that spread hematogenously. These are called “cannon ball tumors.”
17531 – Lymphatic spread and invasion. You can tell this is lymphatic spread because there are no RBCs in the lumen. Lymphatic invasion may be seen in ladies with breast cancer.
10718 – This is a cytokeratin stain that is positive in epithelial types of cancers. It is also seen in adenocarcinoma. Adeno means gland so adenocarcinoma is a gland-like tumor. Adenocarcinomas must be in a lumen. If you see gland like patterns in a lumen it’s an adenocarcinoma.
Liver cancer can be metastatic from just about any GI organ in the abdomen either via lymphatics or by via the portal vein. The renal cancer will not spread to the liver because it almost exclusively spreads via hematogenous routes (via the renal vein to IVC).
18798 –
34652 – Ladies with breast cancer may present with seizures because breast cancer is able to metastasize to the cerebellum.
09441 – This is metastatic mucin producing cells to the brain. When a tumor metastasizes it tends to do it’s same job in the now location. These were originally mucus producing cells so not that they are in the brain they still produce mucus.
25012 – This is xeroderma pigmentosum. Large parts of the diagnosis are based on the history and may be asking about the mechanism of the disease. Does the patient get problems from the sun.
08428 – FAP is familial adenomatous polyposis. FAP is a colon cancer that can progress to adenocarcinoma of the colon.
A tumor is just a swelling, like getting hit in the arm causes a swelling. Neoplasm is a new growth. Neoplasm is actually growth whereas a tumor is any swelling.
Desmoplasm is a neoplasm with fibrous connections. They are hand with lots of desmin.
Adenoma is a benign neoplasm that looks like a gland.
Papillomas are finger like neoplasms that are often associated with keratinized skin.
Cystadenomas are the classic neoplasm of the ovary. Unilateral legions in the women are usually benign. These are most often seen in women under 40. Bilateral pain/legions are usually in women over 40 and malignant.
Carcinomas are a malignant neoplasm of the endoderm or ectoderm.
Sarcoma is a malignant neoplasm of mesoderm like fibrosarcoma.
Sarcomas tend to spread via blood vessels. Carcinomas spread by lymphatic channels so they spread slower then sarcomas giving them a better prognosis. They take longer to get into the blood stream but eventually they will dump into it. Sarcomas also tend to go deeper which helps them hide better and live through treatment.
Mixed tumors have both sarcomic and carcinomic parts.
Tetratomas are mixed tumors that contain material from all three germ layers.
Choritoma is a neoplasm with all of the structures of a given organ but it has not metastasized.
Hamartomas are neoplasms with all the parts of the given organ but they are all mixed up in a strange way.
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Benign |
Malignant |
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Fibroma |
Fibrosarcoma |
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Lipoma |
Liposarcoma |
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Chondroma |
Chondrosarcoma |
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Osteoma |
Osteogenic Carcinoma |
1) CT tumors include:
2) Endothelial tumors:
|
Benign |
Malignant |
|
Hemangioma |
Angiocarcoma |
|
Lymphangioma |
Lymphangiosarcoma |
|
|
Synovial sarcoma |
|
|
Mesothelioma |
|
Meningioma |
Invasive Meningioma |
These CNS tumors are a special case because they do not metastasize outside of the CNS.
|
Benign |
Malignant |
|
Leiomyoma |
Leiomyosarcoma |
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rhabdomyoma |
Rhabdomyosarcoma |
3) Muscle tumors:
Leiomyoma are a common benign tumor of the uterus. About 1/3 of women will get one during their menstruating lives. It rarely becomes malignant. Skin is the most common neoplasm but uterine leiomyoma is the second most common neoplasm.
Rhabdomyomas are neoplasms of the heart, specifically the atria.
Stratified squamous epithelial either of the skin, esophagus or vagina can get squamous cell papillomas or squamous cell carcinoma.
Squamous cell papillomas can also be called condyloma cuneatum. It is the most common neoplasm.
Basal cell neoplasm is usually called basal cell carcinoma but rarely becomes malignant. They usually only spread to other adjacent skin areas and should be called basal cell epithelioma.
GI epithelial tumors include adenoma, adenocarcinoma, papillomas and cystadenoma. Adenomas are the most common and most of them are in the colon within reach of the exam finger.
Neurectoderm tumors are called nevis like the little island next to St Kitts.
If the cells are differentiated they are still doing what they were originally made to do. If they have changed function then they are considered undifferentiated (poorly differentiated).
Size is proportional to metastasis. The larger the neoplasm gets the more likely it is to metastasize.
1) Seeding of cavities. If you remove a cancer and do a sloppy job you will “seed” a cavity. This will put little bits of it all over the cavity and they will grow into lots of tumors.
Ovarian cancer tends to naturally seen the abdominal cavity.
2) Lymphatic spread. Some can cancers have a preference for metastasis to certain nodal chains. If it follows a pattern you can treat by only radiating that given modal chain. Remember that the cancer may not have read the book and may go to the wrong place.
3) Hematogenous spread is via the blood. Renal cell carcinoma likes to spread this way. Cancers with venous spread tend to spread to the lungs. That is how we get so many metastatic lung cancers.
We use the UICC-TNM method to grade tumors. It’s based on:
T (tumor) T0-T4
N (nodes) N0-N3
M (metastasis) M_-M_
The other methods is by the AJC (American joint committee of hospitals) which grades tumors on a scale of 0-IV.
1) The first phase of tumor growth is the tumor’s transformation from normal to neoplastic.
2) Growth phase
3) Invasive phase
4) Metastatic phase
As the tumor is growing you tend to get tumor cell variants. They are mutations of the tumor cells. You then get a big solid malignant mass.
Some require growth factors, some become chemo-resistant, others are non-antigenic.
Smaller neoplasms are usually younger and do not have the heterogeneity of the larger neoplasm. This will cause smaller neoplasms to usually have a better prognosis then larger ones. There are of course exceptions.
In vitro tumors demonstrate:
1) Loss of contact inhibition, they just go anywhere they like.
2) They show reduced serum requirements. They can grow with very little.
3) They do not anchor to any specific site.
4) They fail to mature.
5) Transplantable.
6) They are immortal.
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