2. Tumor
• Definition: A tumor is a mass or lump of tissue
that may resemble swelling.
• a mass of abnormal tissue that arises without
obvious cause from preexisting body cells, has
no purposeful function, and is characterized
by a tendency to independent and
unrestrained (uncontrolled) growth.
• Synonym: Neoplasm
3. • Clinical manifestation:
• Abnormal cells—the kind that generally make up tumors—differ
from normal cells in having undergone one or more of the following
alterations:
• (1) hypertrophy Hyper= increase Trophy= suffix-growth
• an increase in the size of individual cells; this feature is
occasionally encountered in tumors but occurs commonly in other
conditions;
• (2) hyperplasia, or an increase in the number of cells within a
given zone; in some instances it may constitute the only criterion of
tumor formation;
• (3) anaplasia, Ana= backward Plasia= formation
• Loosing morphological characteristics of mature cells
• this is an almost constant feature of malignant tumors,
4. Tumor nomenclature
• The human body is composed of two major classes of
tissue:
1. parenchymal or epithelial tissues
2. mesenchymal tissues, comprising connective tissues,
muscle and blood vessel.
• Benign tumors of most tissues are usually simply
designated the suffix -oma.
• Malignant tumors of the parenchyma are designated the
term carcinoma,
• while malignant tumors of mesenchymal tissues are
designated the term sarcoma
• Carcinoma & sarcoma ---- Malignant
5. • Types of tumors
• Tumors are groups of abnormal cells that form lumps or growths. They can
start in any one of the trillions of cells in our bodies. Tumors grow and
behave differently, depending on whether they are cancerous (malignant),
non-cancerous (benign) or precancerous.
• Non-cancerous tumors/ Benign:
• Tumors that aren’t cancerous are called non-cancerous tumors. Non-
cancerous tumors:
• stay in one place and don’t spread to other parts of the body
• don’t usually come back after they are removed
• may be moved easily with in the tissue
• However, they can cause pain or other problems if they press against
nerves or blood vessels or if they trigger the overproduction of hormones,
as in the endocrine system.
6. • All benign tumors tend to remain localized at the site of origin.
• Why they remain localized?
• tend to have a regular and smooth shape and have a covering called
a capsule
• Many benign tumors are enclosed by a capsule consisting
of connective tissue derived from the structures immediately
surrounding the tumor.
• Well-encapsulated tumors are not anchored(resides) to their
surrounding tissues. These benign tumors enlarge by a gradual
buildup, pushing aside the adjacent tissues without involving them
intimately (closely).
• Malignant tumors, by contrast, do not usually possess a capsule;
they invade the surrounding tissues, making surgical removal
more difficult or risky.
7. • Premalignant: In these tumors, the cells are not yet cancerous, but
they have the potential to become malignant.
• Cancerous tumors/ Malignant :
• Cancer can start in any part of the body. When cancer cells form a
lump or growth, it is called a cancerous tumor.
• A tumor is cancerous when it:
• grows into nearby tissues
• has cells that can break away and travel through the blood or
lymphatic system and spread to lymph nodes and distant parts of
the body
• Cancer that spreads from the first place it started (called the
primary tumor) to a new part of the body is called metastatic
cancer. When cancer cells spread and develop into new tumors, the
new tumors are called metastases.
8. • Metastasis: is thus the outstanding characteristic of malignancy.
Metastasis is the tendency of tumor cells to be carried from their
site of origin by way of the circulatory system and other channels,
which may eventually establish these cells in almost every tissue
and organ of the body.
• In contrast, the cells of a benign tumor invariably remain in contact
with each other in one solid mass centered on the site of origin.
Because of the physical continuity of benign tumor cells, they may
be removed completely by surgery if the location is suitable.
• But the dissemination of malignant cells, each one individually
possessing (through cell division) the ability to give rise to new
tumors in new and distant sites, requires complete eradication by a
single surgical procedure in all but the earliest period of growth.
9. • Examples of benign tumors include:
• Adenomas
• Adenomas develop in glandular (stomach, intestine, colon)
epithelial tissue, which is the thin membrane that covers glands,
organs, and other structures in the body.
• Examples include:
• polyps in the colon (abnormal growth protruding from mucous
membrane)
• Fibro adenomas, a common form of benign breast tumor
• hepatic adenomas, which occur on the liver
• Adenomas do not start as cancer. However, some can change and
become adenocarcinomas, which are cancerous.
10.
11. • Fibroids
• Fibroids, or fibromas, are benign tumors that can grow on the fibrous or
connective tissue of any organ.
• Uterine fibroids are common and can cause:
• vaginal bleeding
• pelvic pain or discomfort
• They can be "soft" or "hard," depending on the proportion of fibers to
cells.
• There are many types of fibroma, including:
• Angiofibromas, Angio- composed of blood vessels & lymphatic vessels
which can appear as small red bumps on the face
• Dermatofibromas, which appear on the skin, often on the lower legs
• Some fibromas can cause symptoms and may need surgery. In rare cases,
fibroids can change and become fibrosarcomas. These are cancerous.
12. • Hemangiomas
• Hemangiomas are congenital benign vascular,
infantle tumor, that form when blood vessels
grow excessively.
• They can appear as red "strawberry marks" on
the skin or they can develop inside the body.
They are often present at birth and disappear
during childhood.
• Hemangiomas do not usually need treatment,
but laser surgery and other options are available
if they do not go away.
13.
14. • Lipoma
• Lipoma are most common in people from 40–60 years
old.
• Lipoma are a form of soft tissue tumor and consist of
fat cells.
• Most lipoma are small, painless, rubbery, soft to the
touch, and movable.
• Location: They often appear on the back, shoulders,
arms, buttocks, and the tops of the legs.
• they are unlikely to become cancerous.
15.
16. • Premalignant
• This type of tumor is not cancerous, but it needs close monitoring
in case it changes.
• Examples include:
• Actinic keratosis
• Also known as solar keratosis,
• It is more likely to affect fair-skinned people, and sun exposure
increases the risk.
• Appearance: is a rough, scaly patch on your skin that develops from
years of exposure to the sun.
• Location: It's most commonly found on your face, lips, ears, back of
your hands, forearms, scalp or neck
• Sometimes, actinic keratosis will transform into squamous
cell carcinoma, so doctors usually recommend treating it.
17.
18. • 3- Malignant
• Malignant tumors are cancerous. They develop when cells
grow uncontrollably. If the cells continue to grow and
spread, the disease can become life threatening.
• Malignant tumors can grow quickly and spread to other
parts of the body in a process called metastasis.
• The cancer cells that move to other parts of the body are
the same as the original ones, but they have the ability to
invade other organs. If lung cancer spreads to the liver, for
example, the cancer cells in the liver are still lung cancer
cells.
• Different types of malignant tumor originate in different
types of cell.
19. • Examples include:
• Carcinoma: These tumors form from epithelial
cells, which are present in the skin and the tissue
that covers or lines the body's organs.
Carcinomas can occur in the stomach, prostate,
pancreas, lung, liver, colon, or breast. They are a
common type of malignant tumor.
• Sarcoma: These tumors start in connective tissue,
such as cartilage, bones, fat, and nerves. They
originate in the cells outside the bone marrow.
Most sarcomas are malignant
20.
21. • Mechanism:
• The total number of cells composing the human body is determined
not only by the rate of proliferation of cells but also by the rate of
cell loss.
• Excess cells and those that are aged or have sustained damage that
impairs normal functioning are eliminated to prevent accumulation
of abnormal numbers of cells.
• The mechanism for regulating the removal of excess and impaired
cells is known as apoptosis.
• Apoptosis: Also referred to as cell suicide or programmed cell
death, apoptosis is an orderly process during which internal cellular
structures are progressively dismantled, the impaired cell shrinks
and finally is rapidly destroyed by immune cells.
22. • While some cell types, such as those that compose the skin and
bone marrow, continue to proliferate throughout life, other types
including bone and muscle cells cease active proliferation when a
human reaches adulthood.
• Most normal cells remain in a non-proliferative state unless they
are stimulated to divide to replace lost cells.
• Abnormal regulation of the cell cycle can lead to the over
proliferation of cells and an accumulation of abnormal cell
numbers.
• Cancer cells arise from one cell that becomes damaged, and when
divided, the damage is passed on to the daughter cell and again to
the granddaughter cells and so on. Such uncontrolled, abnormal
growth of cells is a defining characteristic of cancer
23. • Cause:
• In a healthy body, cells grow, divide, and replace each other in the
body. As new cells form, the old ones die.
• When a person has cancer:
• 1- new cells form when the body does not need them. If there are
too many new cells, a group of cells, or tumor, can develop.
• A neoplasm/tumor can be caused by an abnormal proliferation of
tissues, which can be caused by genetic mutations.
• a mutation occurs near or around tumor suppressor
• Tp53 gene (Tumor protein) that normally inhibits the growth of
tumors) resulting in inability to stop uncontrolled cell division.
24. • Diagnosis:
• A person can sometimes see or feel a tumor, but others will only
show up on imaging tests, such as a mammogram or an MRI.
However, these tests can only detect whether a lump is present.
• A biopsy is necessary to determine the type of lump. The doctor
will take a small sample of tissue and send it to a laboratory where
technicians will examine it under a microscope.
• The doctor may take the sample either in their office, using a
needle, or during a surgical procedure to remove the tumor.
• They may decide that a person needs surgery first if they suspect
that a tumor is malignant or if it is pressing on a nerve or causing
other problems.
• Mammography is the process of using low-energy X-rays to
examine the human breast for diagnosis and screening.
25. • Once diagnosis has been done we grade them
• Grading schemes classify tumors according to the
structure, composition, and function of tumor tissue—
in clinical terms, the histological features of the
tumour.
• The histological grade of a tumor refers to the degree
of tissue differentiation or to an ensemble of tissue
features that have been found to be a good predictor
of the aggressiveness of the tumor. Most grading
schemes classify a type of cancer into three or four
levels of increasing malignancy.
26. Different stages of cancer:
Example: esophageal cancer
• Stage 0 . Abnormal cells (not yet cancer) are found only in the layer of
cells that line the esophagus.
• Stage I . Cancer cells are found only in the layer of cells that line the
esophagus.
• Stage II . The cancer has reached the muscle layer or the outer wall of the
esophagus. In addition, the cancer may have spread to 1 to 2 nearby
lymph nodes (small glands that are part of the immune system).
• Stage III . The cancer has reached deeper into the inner muscle layer or
the connective tissue wall. It may have spread beyond the esophagus into
surrounding organ and/or has spread to more lymph nodes near the
esophagus.
• Stage IV . This is the most advanced stage. The cancer has spread to other
organs in the body and/or to lymph nodes far from the esophagus.
27. • Treatment:
• Squamous cell carcinoma can usually be treated with minor surgery.
doctor may choose to use any of the following techniques to remove it:
• Excision: cutting out the cancer spot and some healthy skin around it,
then stitching up the wound.
• Mohs surgery: excision and then inspecting the excised skin using a
microscope; this requires stitching up the wound.
• Precautions: not used for non-melanoma skin & less than 1cm in size.
• Lymph node surgery: remove a piece of the lymph node; uses general
anesthesia
• Dermabrasion: "sanding" your affected area of skin with a tool to make
way for a new layer
• Cryosurgery: freezing of the spot using liquid nitrogen.
• apply a cold liquid to cancerous cells. The cells are allowed to warm up
and then are frozen again. The cycle of freezing and thawing damages the
abnormal cells.
28. • Topical chemotherapy: a gel or cream applied to the
skin, these are Powerful drugs that attack cancer cells
throughout the body sometimes with microneedling.
• Targeted drug treatment: Newer treatments that
target specific aspects of a cancer to curb cancer
growth and spread.
• Photodynamic therapy (a photosensitizing solution
applied to your skin then activated with a light or
daylight, or sometimes with intense pulsed light.
Targets cancer cells with a special laser light.
• Solution uses: improves efficiency of procedure,
selectivity, targeted method