Neoplasia Pp t

7/31/2019 Neoplasia Pp t

1/65


2/65

Cancer = Latin for crab


3/65

NOMENCLATURE :

Neoplasia - New Growth

Neoplasm Benign, Malignant

Oncology ( Greek oncos = tumor )

In short Growth dysregulation.


4/65

Neoplasia Outline

Tumor

nomenclature Definitions

Benign tumors

Malignant tumors Mixed tumors

Confusing terms


5/65

Definition:

A neoplasm is an abnormal mass of tissue, the growth

of which exceeds and is uncoordinated with that of

normal tissues and persist in the same manner after

cessation of the stimuli which evoked the change. Persistence genetic alteration passed on ,

parent - progeny.


6/65

Tumors are clonal entire population of neoplastic

cells in an individual tumor arises from a single cell.

Benign Tumors Malignant Tumors

Small large

Slow-growing fast growing

Non-invasive invasive

Well-differentiated poorly differentiated

Stay localized metastasize


7/65


8/65

Neoplasm

Benign Malignant

Carcinoma Sarcoma

Classification :


9/65

Benign vs. Malignant


10/65

Benign Tumors Usually designated by adding -oma to cell type

adenomabenign tumor arising from glandular cellsbut may or may not form glandular structures.

leiomyomabenign tumor arising from smoothmuscle cells

chondromabenign tumor arising from chondrocytes Other benign tumor names

papillomahas finger-like projections

cystadenomahas hollow spaces (cysts) inside

polypprojects upward, forming a lump can be benignor malignant.


11/65Thyroid adenoma


12/65Thyroid adenoma


13/65Leiomyoma


14/65Chondroma


15/65Oral papilloma


16/65Oral papilloma


17/65Ovarian cystadenoma


18/65


19/65Ovarian cystadenoma


20/65

Malignant Tumors Carcinomasarise in epithelial tissue ( 3 germ cell layers)

adenocarcinoma tumor cells grow in glandular pattern. squamous cell carcinoma tumor cells resemble stratified

squamous epithelium.

Sarcomasarise in mesenchymal tissue chondrosarcomamalignant tumor of chondrocytes

angiosarcomamalignant tumor of blood vessels

rhabdomyosarcomamalignant tumor of skeletal muscle cells
http://www.microscopyu.com/galleries/pathology/ovarianadenocarcinoma.html


21/65Adenocarcinoma
http://www.microscopyu.com/galleries/pathology/ovarianadenocarcinoma.html


22/65Squamous cell carcinoma


23/65Rhabdmyosarcoma


24/65

Mixed Tumors

Mixed tumors divergent

differentiation along two lineages.

Examples

pleomorphic adenoma glands + fibromyxoidstroma

fibroadenoma glands + fibrous tissue

Not to be confused with teratomasarises from all three layers.


25/65Pleomorphic adenoma


26/65


27/65


28/65


29/65


30/65

Hamartomas : disorganized but benign appearing

masses composed of cells indigenous to a particular

site.eg:- pulmonary chondroid hamartoma

Choristoma: heterotopic rests of well developed and

normally organised tissue.eg:- normal pancreatic tissue in stomach,

duodenum.


31/65

Definitions

Differentiation-extent to which

neoplastic cells resemble normal cells

both morphologically and functionally

Anaplasialack of differentiation

wherein reversal of differentiation to a

more primitive level.


32/65

Pleomorphism variation in size &shape

Abnormal nuclear morphology hyperchromatic

Mitoses especially bizzare atypical mitoses Loss of polarity

Metaplasia

replacement of one type of cell withanother type due to damage, repair or

regeneration. eg: GERD

Dysplasia literally means disordered growth.

Characterized by a constellation of changes thatinclude a loss in the uniformity of the individual cells as

well as a loss in their architectural orientation.


33/65

Cell nuclei become hyperchromatic

Nuclear membranes become irregular

Nuclear to cytoplasmic ratio increased.


34/65


35/65


36/65


37/65

DYSPLASIA

-65yr old tobacco chewer

-oral mucosa shows leukoplakia

(white plaque)-full thickness severe dysplasia

on mucosal biopsy


38/65

GROWTH

Concept:

Benign tumours grow slowly

Cancers grow rapidly


39/65

RATE OF GROWTH

Rate of Growth is determined by three main factors :

(1) The doubling time of tumour cells.

(2) Fraction of tumour cells in replicative pool.

(3) Rate at which cells are shed or die.

Growth Fraction :Proportion of cells with in the tumour population thatare in the proliferative pool (Cancer chemotheraphy).

Aggressive tumours Lymphoma, leukemias melt

with CTCancer of colon and breast Debulk cell cycle Drugtherapy


40/65

BENIGN VERSUS MALIGNANT

TUMOURS

Invasion

Distinguish

malignant

tumours

Metastases


41/65

INVASION

Definition :Growth into the surrounding tissue by directextension / expansion.

Benign tumours

Expansile probing margins

Localized growth

Do not have the capacity to infiltrate

May have a capsule or clear line of separation If resected to not recur

If incompletely removed local recurrence only


42/65

Malignant tumours :

Progressive growth

Infiltration ~ poor line of demarcation

Invasion Destruction of adjacent tissue

Metastatic spread

Death if not treated


43/65

METASTASIS

Spread of tumour to distant sites bylymphatic, hematogenous routes or seeding ofbody cavities.

About 30% of tumours present withmetastases

Poorly differentiated tumours more likely tospread


44/65


45/65

1. Detachment of tumour cells

Down regulation of E- cadherin expression

Eg : Adeno Ca of colon

Ca of breast

Reduced expression of protein catenins that

links E cadherin to cells cytoskeleton.


46/65


47/65

(b) Down regulation of anti - proteases


48/65


49/65

4. Invasion of the circulation :

Matrix metalloproteinase.

Down regulating antiproteases.

5. Homing of tumour cells

Adhesion of tumour cells to endothelium Degradation of vessel wall

Organ tropism.

- Tumour cells express adhesion molecules whose ligands

are expressed on vascular endothelial cells of target organ. - Preference for metastasis to specific organ are explained

by chemokines. ( LN, Lung express CXCR4 and CCR7 )

- Eg : Prostatic Ca Vertebral boneNeuroblastomas Liver, Bone.

M t t ti d


50/65

Metastatic cascade


51/65

PATHWAYS OF SPREAD

Seeding of body

cavities and surfaces

Lymphatic spread

Hematogenous spread


52/65

Types :

1. Direct Spread :Direct infiltration of malignant cells into adjacent

tissue, lymphatic or blood vessels.

(1) Local spread

(2) Lymphatic invasion

(3) Perineural invasion

(4) Venous invasion

(5) Arterial invasion.


53/65

Osteogenic sarcoma

Pagetoid spread


54/65

Tumour infiltrating

into the adjacent

duct and spread

between theepithelial lining and

the myoepithelial

cell lining the BM of

duct

Eg : Breast Ca

Perineural Invasion

Adenoid cystic carcinoma


55/65

Lymphatic spread Sentinel lymphnode :

The first lymphnode in a regional lymphatic drainage that gets involved bytumour metastasis.

Eg : Sentinel lymphnode mapping is important in - breast carcinoma

- Melanoma

- Colonic Ca

Breast Ca spread through lymphatic

and large in sub capsular sinus


56/65

Retrograde embolism :

Embolisation of tumour in the reverse

direction to unusual sites when the flow of

lymph is blocked by tumorous permeation.

E.g. : Gastric cancer cells blocks the lymphatic

drainage thoracic duct into the left

subclavian left cervical nodes. ( Virchow )

Enlarges ( Troisiers sign )


57/65

Blood Vascular spread


58/65

ood ascu a sp ead


59/65


60/65


61/65


62/65


63/65

Transcoelomic spread

Malignant cells detached and fall through the natural spaces andspread.

(1) Spread through peritoneal cavity.

Krukenberg tumour : (Ovarian metastasis)

- Ca of stomach, colon, breast infiltrate the peritoneal layer and thenfall through the abdominal space due to gravity and settle on theovaries

- Ovaries are enlarged capsule is smooth and intact.

- Cut section shows diffuse replacement of the ovary by mucinsecreting Ca.

Pseudomyxoma peritonei :

- Mucin secreting adeno Ca of appendix or ovary rupture, dischargethe mucin and tumour cells into the peritoneal cavity.

- The tumour cells grow and secrete large amount of mucinousmaterial filling the abdominal cavity.


64/65

METASTASES

LIVER

METASTASES

FROM A

PRIMARY

BREAST

CARCINOMA

normal

liver

function

tests!

CANCER


65/65

CANCER

one out of every five people who die thisyear will die of tumors

Documents

Neoplasia Pp t