1,2 - Neoplasia Flashcards
Neoplasm
- Clonal proliferation of cells, the growth of which is autonomous and not coordinated with normal growth
regulatory mechanisms - Cells with proliferative capacity
- Mutations in DNA
- Irreversible phenotype
How are neoplasms classified
Benign
vs.
Malignant
Characteristics of benign neoplasms
Benign Neoplasms
- Grow slowly
- Do not invade adjacent tissues or metastasize
- Often are encapsulated
- Closely resemble cell of origin (differentiated)
- Uncommonly cause patient death
Characteristics of malignant neoplasms
- Grow more rapidly
- Invade adjacent tissues and have potential to
metastasize - Not encapsulated, desmoplasia
- Less closely resemble cell of origin
- More likely to cause patient death
Visual characteristics of a desmoplastic reaction (H&E)
desmoplastic=fibrous or connective tissue around cells
nomenclature of neoplasms
- General rules
- cell type + “oma” = benign neoplasm
- cell type + “carcinoma” = malignant neoplasm of
epithelial origin - cell type + “sarcoma” = malignant neoplasm of
mesenchymal origin - May add descriptive modifiers (e.g. papillary, cystic)
- Some neoplasms contain mixed elements (e.g.
fibroadenoma, carcinosarcoma)
nomenclature of neoplasms - special exceptions to general rule
- Exceptions to general rules exist
- Teratoma – neoplasm arising from germ cells
containing elements from different embryonic layers
(benign or malignant) - Hamartoma – disorganized normal tissue due to
impaired embryonic development (? true neoplasm) - Lymphoma, Melanoma, Hepatoma (actually all
malignant neoplasms)
morphology of neoplasms
- Differentiation – degree of resemblance to normal
cell of origin - Anaplasia – lack of differentiation
- Pleomorphism – variation in cell size and nuclear
appearance - Mitotic rate – reflects proliferative rate
- Necrosis – outgrow blood supply
What does a well-differentiated neoplasms look like (h&e)?
What does a less-differentiated neoplasms look like? (H&e)
What does neoplastic differentiation dyregulation look like in adenocarcinoma?
What is anaplasia? What does it look like in small cell carcinoma?
Anaplasia – lack of differentiation
What are pleomorphism and mitotic figures? What do they look like?
- Pleomorphism – variation in cell size and nuclear
appearance - Mitotic rate – reflects proliferative rate
How do neoplasms become necrotic? What does that look like?
Necrosis – outgrow blood supply
What are adjuncts (aids) for identifying the morphology of neoplasms?
- Morphology adjuncts
- Cytochemical stains
- Immunohistochemistry (cytokeratin, vimentin,
leukocyte common antigen, Ki-67)
cytokeratin= epithelial cells; vimentin=
mesenchymal cells; Ki-67= proliferative cells - Electron microscopy
- Tumor markers
What does a mucin stain adjunct look like for identifying neoplasms?
What cytochemical stains are used as adjuncts to identify neoplasms? What does a cytochemical stain adjunct look like for identifying neoplasms?
What does a TEM adjunct image look like for aiding in identifying neoplasms?
What are some clinical tumor markers for identifying neoplasms?
What factors affect and are used to describe the growth of tumors?
- Doubling time (replicative rate)
- Growth fraction
- Death (apoptotic) rate
- Variable over time
- Influences (blood supply, hormonal stimulation)
How is the invasion and spread of neoplasms classified/described?
- Carcinoma in situ
- Microinvasion
- Frank invasion
- Metastasis
How do we describe/classify metastasis of neoplasms?
- Seeding of body cavities
- Lymphatic spread (lymph node metastasis)
- Sentinel lymph node
- Hematogenous spread (distant metastasis)
Characteristics of implantation metastases
Characteristics of distant lymph node involvement in metastasis
Characteristics of metastatic carcinoma (visualization)
Characteristics of blood-borne metastasis
Grading and staging of neoplasms
- Used to predict the behavior of neoplasms (prognosis)
and determine appropriate therapy - Grading – assessment of degree of differentiation and
proliferative capacity - Staging – assessment of tumor size and extent of
spread locally and distantly
staging of neoplasms in colorectal cancer
broadly, what classes of agents are carcinogens?
- Viruses
- Chemical agents
- Physical agents (ionizing radiation)
- Chronic inflammation (RCV)
What are important aspects of carcinogenesis?
- Multistep process
- Successive DNA mutations (failure to repair)
- “Neoplastic” phenotype
- Clonal expansion
- Clonal progression (tumor heterogeneity)
Acquired and successive DNA mutations progression in carcionogenesis
clonal progression and tumor cell heterogeneity in carcinogenesis
clinical effects of neoplasms
- Benign neoplasms
- Location
- Hormone production
- Progression to malignant neoplasm
Paraneoplastic syndromes
- Fever
- Cachexia
- Ectopic hormone production (endocrine syndromes)
Cushing syndrome - paraneoplastic basis
A condition that occurs from exposure to high cortisol levels for a long time.
cushing syndrome - paraneoplastic appearance
hypercalcemia - paraneoplastic syndrome
carcinoid syndrome - paraneoplastic syndrome
Clinical syndromes arising from paraneoplastic effects from underlying cancer and causal mechanisms
paraneoplastic syndromes
cushing syndrome - what underlying cancer and causal mechanism?
syndrome of inappropriate antidiuretic hormone secretion - what underlying cancer and causal mechanism?
Hypercalcemia - what underlying cancer and causal mechanism?
hypoglycemia - what underlying cancer and causal mechanism?
carcinoid syndrome - what underlying cancer and causal mechanism?
polycythemia - what underlying cancer and causal mechanism?
body systems affected by paraneoplastic syndrome, how are they affected?
- Hematologic [(anemia, thrombosis, disseminated
intravascular coagulation(DIC)] - Neuromuscular (neuropathy, myasthenia)
- Gastrointestinal (malabsorption, hypoalbuminemia)
- Renal (nephrotic syndrome)
- Cutaneous (acanthosis nigricans, Leser-Trelat sign)
Venous paraneoplastic syndrome - Trousseau syndrome
cutaneous paraneoplastic syndrome - acanthosis nigricans and leser-trelat sign
Venous paraneoplastic syndrome - thrombotic vegetations on heart valve
Epidemiology of neoplasms
- 20% of total mortality in the US
- Epithelial cancers (lung, colon, breast, prostate) are
most common in adults - Leukemia, lymphoma, CNS neoplasms are most
common in children - Geographic differences in incidence
- Environmental associations (carcinogens)
syndrome of inappropriate ADH secretion by small cell lung cancer
