Characteristics of malignancy- refer to printed lecture 15 Flashcards
What are the roles of the parenchymal component and stroma component?
> parenchymal component represents the transformed element
> The stroma is critical for the growth of the tumor but cannot be used to differentiate a benign from a malignant*the amount of stroma can aid in the consistency of the tumor and thus a carcinoma that has abundant stroma is called a desmoplastic
What is the difference between benign and malignant in terms of differentiation
Benign are well-differentiated ( benign cells are similar to normal cells morphologically ) and malignant have a poor range of differentiation( look different from normal cells/cell of origin (from well differentiation to poorly differentiation )
What are anaplastic cells and how can they be identified?
- Anaplastic means to form backward= dedifferentiate
- Anaplastic cells: pleomorphic cells, variable nuclei, and bizarre size and hyperchromatic with numerous and atypical mitosis
What are the characteristics of benign type?
> A benign neoplasm is similar to the tissue with normal cells
Do not invade surrounding tissues and do not metastasis
slow growth
Well differentiated
Circumscription
Lack of invasion
Absence of metastases
> Arise usually in a solitary manner : lipoma of colon ,meningioma of brian
> May be multiple : leimyomata of uterus , intradermal nevi of skin
> Through benign ,they may cause problems through mass effects ,particulary in tight quaters - pituitary adenoma in the sella turcica
Characteristics of malignant tumors?
> Cells look less like normal cells of origin
Higher rate of proliferation
Can It can potentially invade and metastasize
More rapid increase in size
less differentiation (or lack differentiation -anaplasia)
Tendency to invade surrounding tissue
able to metastasize to distant tissues
The growth rate of malignant cells correlates with the differentiation of the tumor(poor differentiation grows faster and better will grow slower
Cytological features of malignant neoplasms include?
- increased nuclear size (increased nuclear/cytoplasmic size N/C ratio
- Variation in nuclear size (pleomorphism )
- Lack of differentiation - anaplasia
- Increased nuclear or cell size (dark staining on Hand E slides, hyperchromatic )
- Prominent nucleoli or irregular chromatin distribution within nuclei
- Mitosis -irregular or bizzare mitosis
What the macroscopic differences between benign and malignant tumors?
> BT is round whereas Mt are irregular masses.
Bt are smooth surface whereas MT are irregular surface
BT is uniform cut whereas MT are uneven cut surface
BT are not attached to the surrounding tissues whereas the MT are attached to skin or fixed to deep strctures
Does not recurr after excision whereas MT tends to recur after excision
Diagnostic methods for neoplasia
- History and physical examination
* Talking to patient
* direct examination may give clues to the presence of a neoplasm
* Signs and symptoms such as weight loss, fatigue, and pain
* A mass may be palpable or visiable - Radiographic techniques
* Plain x-rays
* Computed tomography (CT)
* Magnetic resonance imaging (MRI)
* Mammography
* Ultrasonography (US)
* Helpful to detect the presence and location of mass lesions
Laboratory analysis of tumors?
Refer back to notes
- Findings such as anemia, enzyme abnormalities (increased alkaline phosphatase ), and hematuria or positive stool occult blood
- Tumor markers in serum
Genetic Testing for tumors
- Genetic markers include chromosomal alterations
- Specific gene defects
- Gene rearrangements
- Detection of specific genes such as BRCA-1
Cytology for tumors
- Methods that sample cells can be simple and cost-effective and minimally invasive
- pap smear for diagnosis of cervical dysplasia and neoplasm
- Cells exfoliate into body fluids may also be examined
- fine needle aspiration can be used to sample a mass lesion
Tissue biopsy and surgery
- Sampling small pieces of tissue (biopsy) at a particular site via endoscopy techniques can yield a specific diagnosis of malignancy
- At surgery ,portions of an organ or tissue can be sampled or diseases tissue removed and examined in surgical pathology to determine the stage and grade of the neoplasm
How can tumors be graded
Roman numerical
Grading refers to the differentiation of the tumor
- Well differentiated
- Moderately differentiated
- Poorly differentiated
- Nearly anaplastic
A benign tumor does not need grading
Tumor Staging
Tumor staging tells us about the stage of the disease
Often give as TNM status
> Tumor
- Tis In situ,non-invasive (confined to epithelium )
- T1 =small, minimally invasive within primary organ site
- T2= Larger, more invasive within the primary organ site
- T3=Larger and/or invasive beyond margins of primary organ sites
- T4= Very large and/or very invasive spread to adjacent organs
> Lymph nodes involvement *N0; No lymph node involvement N1: Nearby lymph node involvement N2: Regional lymph node involvement N3: More distant lymph node involvement
> Metastasize
- M0; No distant meetastases
- M1 ; Distant metastases present
Tumor treatment and prognosis
- Surgery: Cutting out the neoplasm ( it is still the most effective treatment)
- Radiation: Effectiveness depends upon the radiosensitivity of the tumor and the body’s ability to tolerate radiation dose
- Chemotherapy: Effectiveness depends upon the ability of the drugs to selectively poison the neoplastic cells and not the normal cells
Some neoplasms can be influenced by hormonal therapy ( estrogens inhibit prostatic adenocarcinoma, antiestrogen therapy inhibits breast adenocarcinoma )
