Neoplasia I

• Tumour

• Cancer (Malignant)

• Carcinoma/sCarcinogenesis; Process involved in

development of all types of malignant neoplasm .

• Oncology; Oncogenesis; Changes involved in the

development of any kind of neoplasm.

• Neoplasia: is a result of pathological proliferation of cells.

Definition: • The purpose less excessive proliferation

which continue indefinitely (irreversible) even after removing the initial stimuli with an un coordinated manner to the requirement of the surrounding tissues or the individual.

• Autonomous growth: un control growth

BUT Nutrition and HOST Stromal tissue

• Parasitic in behaviour

• Tumours vary mostly in structure and behavior

• This variation depend on,

Type of cells from which neoplasm developed

Degree of differentiation achieved Whether the neoplasm is Malignant or benign

Tumours - Benign ;

No propensity to metastasis•Localized, slow growing •Symptom less (pressure,Hormonal)•No invasion/Can excised completely •Few mitosis but normal •Encapsulated/ No metastasis•Mimic the structure of the parent organ, resembles the cells of origin (uniform cells) (Well differentiated).

Malignant:• Rapidly growing• Invasive (margins are not clear)

• Vary in size and shape (cells/nuclei) • Frequent and abnormal mitosis.• Bear little resemblance to the mother tissue (Less well differentiated)• Metastatic - Loss of adherence Spread through blood and

lymph

Differentiation: Extent of resemblance to the mother tissue or adult cells of the tissue of origin both in

Morphology (Cell-cell, Cell to stroma) Functionally

• Well differentiated• Moderately differentiated.

• Poorly differentiated .

• Anaplasia; Complete loss of resemblance to the mother tissue (Lack of differentiation).

Degree of differentiation is assessed by using cellular atypia.

• Degree of differentiation is assessed by using cellular atypia.

• Size shape/ of the cell (Pleomorphism)• Arrangement in relation to one

another/stroma/bld • Disorganized growth of groups or sheets of cells. • large distorted nuclei/ multi nucleated • High nuclear/cytoplasm ratio • Hyperchromatism• Abnormal mitosis/ increase mitosis

Dysplasia

• Group of changes that can be seen principally in epithelia which would lead to disorganise the tissues

both in cellular level

organisation level

• Histopathological description of epithelium in which cellular atypia present

• Dysplastic changes: Cellular changes which characterize in malignant

and premalignant lesions. Neuclear /cellular pleomorphism Altered neuclear cytoplasm ratio. Hyperchromatism Abnormal mitoses/ more mitoses Loss of polarity/ loss of stratification Individual cell keratinisation Basel cell hyperplasia. Drop shaped rete pegs

How does neoplasia differ from hyperplasia

• Spontaneous growth

• Growth is not related to the degree of stimulus and once it starts proceeds irrespective of the stimulus.

• Once stimulus removes the lesion progress

Classification of tumours• Naked eye appearance: eg; Annular, Fungating, Scirrhus tumours

• Aetiological : Unknown agents

Single agent –different types of tumours

Different types of agents –Single tumours

• Functional: Insulinoma, Glucagonoma

• Behavior:

Benign, Malignant

Intermediate: Locally aggressive No metastasis

Low metastasis

Metastasized but progress slow

Eg; Basal cell Carcinoma Ameloblastoma

• Spontaneous regression; Malignant melanomas, Choriocarcinoma, Clear cell carcinoma of the kidny, Neuroblastoma, Burkitt lymphomas (small dose of cytotoxic agents)

• Latent cancer ; Proliferating mass of cell has all the histological features of malignancy even invasion of blood and lymph, However , they are clinically silent with no metastasis.

• Dormant cancer: Late appearance of metastatic tumour after successful removal of the primary tumour.

No local recurrence Patient is quite well in between Tumour comes out with a serious illness.-

• Histogenetic; Based on the type of tissue origin

Tumours of epithelial Epithelial Tumours of connective tissue

• Problems• Tumours arising from endothelium or mesothelium

resemble the tumours of epithelial in origin.

eg mesotheliomata adenocarcinoma of the lung.• Undifferentiated tumours• Tumour metaplasia• Tumours arising from embryonic tissues. Certain

tumours arising from cells that are present in development but disappears in the adult life.

• Histologic classification:

Tumour metaplasia

Anaplasia

• Undifferentiated salivary tumours which have no glandular appearance will name as polygonal spheroidal,

• Carcinoma simplex. The anaplasia is so great that it is uncertain whether the origin is epithelial or connective tissue.

In new Classifications

• Behavior,

• Tissue of origin

• supplemented with histological description.

• Nomenclature : Epithelial, (Benign or Malignant) Mesenchymal (Benign or

Malignant)

• Neoplasia - Parenchyma (Neoplastic cells) (Nature) Stroma (Growth/ evolution)

Eg: Flashy tumours (scanty stroma)

Scirrhous tumour of the breast Desmoplasia(abundant stromal reaction)

• The nomenclature of benign mesenchymal tumours:

• parenchymal component is named histologically

Chondro, osteo, lipo, fibro, etc

• OMA - Benign tumours

•Benign mesenchymal tumours are named histogenetically according to parenchymal cell type

•Muscle = leiomyoma, rhabdomyoma•Bone =osteoma•cartilage = chondroma• fat = lipoma•vessel = angioma•fibrous tissue = fibroma

Benign epithelial tumours Microscopic, Macroscopic,

Histogenecity • Neoplasm arising from benign epithelium containing

microscopic or microscopic finger like or papillary projections

Papilloma.

• Neoplasm arising from benign epithelium which forms a glandular pattern or directly arising from glandular tissues(not necessarily look like glands).

Adenomas (renal tubular adenomas)

•Degree of differentiation is assessed by using cellular atypia.

• Malignant tumours;

• Tumours arising from mesenchimal tissues with malignant nature “Sarcoma”

• Muscle = Leiomyoma, Liomyosarcoma Rhabdomyoma Rhabdomyosarcoma

• Bone = osteoma Osteo sarcoma

• cartilage = chondroma Chondrosarcoma

• fat = lipoma Liposarcoma

• vessel = angioma Angiosarcoma

• fibrous tissue = fibroma Fibrosarcoma

• Malignant neoplasms of epithelial cell origin (derived from any of the germ layers) “Carcinoma”

eg; Epidermis, GIT, Renal tubular

• The carcinomas will be further specified as adenocarcinoma, squamous cell carcinoma

• Further specify eg renal cell adeno carcinomas, bronchogenic SCC.

Mixed tumours; • Benign or malignant cells in tumours resembles

to each other to a certain extant.(as they arise from one cell)

• But sometimes divergent differentiations in a single line of cells have been observed. The result will be mass of cells with different types of tissues. However, most of these tumours represent single germ layer. (Pluripotential cell)

• They will be named as “mixed” Eg; pleomorphic adenoma (epithelial or myoepithelial cells of the salivary origin)

Teratoma; Most of the tumours including mixd tumours arise from single germ layer.

Teratomas: • consist of variety of parenchymal cell types

representing more than one germ layer. • It is believed that they arise from totipotential

cells of primitive cell rest and differentiate along different germ lines and produce different types of cells and there by different types of tissues.

• Totipotent cells are encountered in gonads or rarely any where sequestered primitive cell rests are available

• Totipotential cells differentiates alone various germ layers produce different types of tissues such as Skin, Muscle, Fat, Gut Epithelium, teeth etc--

• However some believe that teratomas arise from germ cells. (Commonly seen in gonads)

• Definition: Tumour consist of multiple tissues chaotically arranged and foreign to the part from which its arises.

Hamatomas:Hamartoma is a tumour like malformation in which

the tissues of a particular part of the body are arranged haphazardly usually with an excess of one or more of its component.

• Differentiation is aberrant• Arrangement is disorganised • Cells are mature and indigenous to the site

Eg 1: Haemangioma, 2: Hamartoma in lung tissue Hyaline cartilage is similar to found in the bronchi There are clefts lined with respiratory epithelium In the middle smooth muscle and connective tissues.

Differ from teratomas.

• The tissues specific to the site/No capsule

• No tendency towards excessive growth

• Comparison• Benign• Circumscribed• Encapsulated• Not

• Slow/ stops latter• Compress the normal

surrounding tissue• Structurally and

functionally well differentiated

• Malignant• Irregular in shape• Not encapsulated• Ulceration an

haemorrhage is common

• Growth is rapid• Invade and destruct

the normal tissue • Less well

differentiated or anaplastic

• Death- due to pressure effects/hormonal effects/obstructions

• Function –Maintains• Expansive growth• No• Regular

• Little increase/normal• Normal• Little tendency• Small size

• Death- due to destructive effects/blood loss/ infections/starvation/malnutrition/anaemia

• altered• Infiltration, invasion, • Metastasis • Nuclear and cellular atypia• Increase mitosis/abnormal• Cellular adhesion is weak• Necrosis common• Large size

• Sarcoma

• Less common• Young people• The parenchymal cells

arranged in diffuse sheets and integrated with stroma

• Poorly formed stroma• Haemorrhage/necrosis

extensive• Fast growing• Lympahtic spread

uncommon • Very early blood borne

metastasis• Radioresistant

• Carcinoma• Common• Middle/Old aged • Parenchymal cells

arranged in groups or columns

• Well formed stroma• Haemorrhage/necrosis

less extensive• Comparatively slow• Early lymphatic spread

is common• Little late• Radiosensitive

• Ovarian teratomas:

• Well differentiated, benign, seen young or middle age women

• Histologically; Thin-walled cystic mass filled with sebaceous keratinous debris and matted hair.

• Wall is usually stratified squamous epithelium.

• In the eminence of the wall-Teeth, tongue like structure, even bone and cartilage, other types of epithelia and nerves tissues.

• Rarely entire teratoma has a one type of tissue eg Struma ovarii (Thyroid tissues)

• Rarely entire teratoma has a one type of tissue eg Struma ovarii (Thyroid tissues)

• Malignant changes are uncommon

• Rarely described a solid type which is malignant.

• Testicular teratoma

• Young middle aged males/ some in children (benign) .

• Majority highly malignant

• In malignant variety - Malignant intermediate Malignant undifferentiated

• The less malignant types consists irregular gland like spaces lined with atypical cells which may resemble squmamous respiratory and intestinal epithelium in different places.

• Masses of cartilage bones muscles etc seen

• All is supported by connective tissue stroma.

• Highly malignant types glandular pattern with papillary convolusions

• Malignant tropoblastic types has tropoblast cells in addition to other types of cells.