neoplasia introduction

NEOPLASIANEOPLASIADr.CSBR.Prasad, M.D.,Dr.CSBR.Prasad, M.D.,

• Metaplasia• Dysplasia• Anaplasia• Complication of chronic inflammation /

irritation

Clinical examples of Neoplasia

Nomenclature

• Neoplasia • Neoplasm• Tumor• Oncology• Clonal / Clonality• Benign• Malignant (Latin)• Cancer

Neoplasia - Definition

• Neo = New

• Plasia = Growth Neoplasia = New growth• Tumor = Swelling• Cancer = Crab (L)

• Oncology = Study of tumor / Neoplasm (Oncos = Tumor)

Nomenclature• Normal• Abnormal

– Non neoplastic• Hyperplasia• Metaplasia

– Precancerous (dysplasia / in situ carcinomas)

– Neoplastic• Benign

– Epithelial– Mesenchymal

• Malignant– Epithelial– Mesenchymal

Cancer (L. Crab)• Any malignant growth of cells (clonal)• Nearly 7 lakh people die of cancer in

India (2015)

Gross features Microscopic featuresGross features Microscopic features

Cancer (L. Crab)

The following figure shows how cancer cases have been progressively increasing from 2004 to 2010

Definition• “Willis” definition of Neoplasia - (new growth)

abnormal mass of tissue, the growth of which exceeds and is uncoordinated with the normal tissues and continues to grow even after the cessation of the stimulus that evoked the initial response

• New Definition: (Robbins Path) a neoplasm can be defined as a disorder of cell growth that is triggered by a series of acquired mutations affecting a single cell and its clonal progeny

Normal – Hyperplasia – Dysplasia – Carcinoma

Neoplasm

The causative mutations give the neoplastic cells a survival and growth

advantage, resulting in excessive proliferation that is independent of

physiologic growth signals (autonomous)

Makes an interesting reading…

Neoplasia

• It is autonomous, purposeless• Proliferation is uncontrolled• Competes with normal cells for its needs• It is a clonal disorder• It is a genetic disorder

– In 95% of cases acquired genetic disorder– In 5% of cases inherited

Nomenclature

• All tumors have two components– Parenchyma

• Represents tumor proper; the growth of the tumor is due to proliferation of these cells

– Stroma• Provides the framework, blood supply and nutrition

for the parenchymal cells

ParenchymaParenchymaStromaStroma

Desmoplasia

• Formation of abundant collagenous stroma• Stimulated by parenchymal cells

• Ex: Schirrous. ca of breast Linitus plastica (ca stomach) Carcinoma prostate

Scirrhous carcinoma of breast

Linitus plastica

Nomenclature

• Tumors are designated by attaching suffix “–oma” to the cell or tissue of origin– Fibroma, chondroma, lipoma, osteoma etc– Benign tumor arising from glandular structure is called

adenoma– Benign tumor arising from epithelial surface having finger

like projections is called papilloma– Malignant tumor arising from epithelial tissue is called

Carcinoma– Malignant tumor arising from mesenchymal tissue is called

Sarcoma

Papilloma / Polyp / Adenoma


Pedunculated polypSessile polyp

Tissue of Origin Benign MalignantComposed of One Parenchymal Cell TypeTumors of mesenchymal originConnective tissue and derivatives

Fibroma Fibrosarcoma

Lipoma Liposarcoma Chondroma Chondrosarcoma Osteoma Osteogenic sarcomaEndothelial and related tissuesBlood vessels Hemangioma AngiosarcomaLymph vessels Lymphangioma LymphangiosarcomaSynovium Synovial sarcomaMesothelium MesotheliomaBrain Coverings Meningioma Invasive

meningioma

Tissue of Origin Benign Malignant

Blood cells and related cells

Hematopoietic cells Leukemias

Lymphoid tissue Lymphomas

Muscle

Smooth Leiomyoma Leiomyosarcoma

Striated Rhabdomyoma Rhabdomyosarcoma

Tumors of epithelial originStratified squamous

Squamous cell papilloma

Squamous cell carcinoma

Basal cells of skin or adnexa

Basal cell carcinoma

Epithelial lining of glands or ducts

Adenoma Adenocarcinoma

Papilloma Papillary carcinomas Cystadenoma Cystadenocarcinoma

Respiratory passages

Bronchial adenoma

Bronchogenic carcinoma

Renal epithelium Renal tubular adenoma

Renal cell carcinoma

Liver Cell Adenoma Hepatocellular carcinomaUrothelial cell Papilloma Urothelial carcinoma

Placental epithelium Hydatidiform mole Choriocarcinoma

Testicular epithelium (germ cells)

Seminoma

Embryonal carcinoma

Melanocytic Tumors Nevus Malignant melanoma

More Than One Neoplastic Cell Type-Mixed Tumors, Usually Derived from One Germ Cell Layer

Salivary glands Pleomorphic adenoma (mixed tumor of salivary origin)

Malignant mixed tumor of salivary gland origin

Renal anlage Wilms’ tumor

More Than One Neoplastic Cell Type Derived from More Than One Germ Cell Layer-Teratogenous

Totipotential cells in gonads or in embryonic rests

Mature teratoma, dermoid cyst

Immature teratoma, teratocarcinoma

Tissues with NO benign tumors

• Synovium• Mesothelium• Lymphoid tissue• Hematopoietic cells• Basal cells of skin or adnexa

Nomenclature• Malignant tumor arising from epithelial

structures is called “Carcinoma”• Malignant tumor of the mesenchymal tissues

is called “Sarcoma”• Embryonal tumors usually have the suffix

“Blastoma”• Malignant lesions of the blood are called

“Leukemia”• Malignant lesions of the lymphoid tissue is

called “Lymphoma”

Neoplasms of Totipotent Cells

Neoplasms of Embryonic Pluripotent Cells

• Pluripotent cells can mature into several different cell types

• These neoplasms are generally called Embryomas or Blastomas

Blastoma• All blastomas are childhood tumors• All blastomas are malignant tumors

Except: – Chondroblastoma– Osteoblastoma– Pulmonary blastoma

Neoplasms of pluripotent embryonic-type cells (BLASTOMAs)

Nomenclature of Neoplasms of Differentiated Cells

Exceptions to These Rules

• Neoplasms That Sound Benign But Are Really Malignant

• Neoplasms That Sound Malignant But Are Really Benign

• Leukemias• Mixed Tumors• Neoplasms Whose Cell of Origin Is

Unknown

Lymphoma Plasmacytoma

Melanoma Glioma

Astrocytoma

OsteoblastomaChondroblastoma

Nomenclature• Some malignant tumors named like benign

tumors– Melanoma, Hepatoma, Lymphoma

• Some benign tumors named like malignant tumors– Cystosarcoma phylloides, chondroblastoma

• Some unusual tumors– Mixed tumor of salivary gland (pleomorphic adenoma)– Teratoma

Mixed tumor

• Tumors with single type of parenchymal cells that differentiates into many cell lines– Eg: Pleomorphic adenoma of salivary gland.

Pleomorphic adenoma - Parotid

Teratoma

• Tumor arising from totipotent cells (germ cells) showing differentiation towards tissues derived from all the three germ cell layers– Seen usually along the midline– Common sites

• Ovary, testis, sacro-coccygeal region, retro-peritoneum, mediastinum, base of the brain etc

What are the common sites for teratomas ?

• Gonads• Mid line• Lines of fusion

Along the lines of fusion

Neoplasms of Totipotent Cells

Sacrococcygeal teratoma

Teratoma

Named tumors

Hamartomas & Choristomas• A hamartoma is composed of tissues that are

normally present in the organ in which the tumor arises– Eg: a hamartoma of the lung consists of a disorganized

mass of bronchial epithelium and cartilage that may become so large that it presents as a lung mass. Its growth is coordinated with that of the lung itself

• A choristoma resembles a hamartoma but contains tissues that are not normally present in its site of origin– Eg: A orderly mass of pancreatic acini and ducts in the

wall of the stomach is properly called a choristoma.

Sarcomas are very vascular -local rise of temperature

Hamartoma• Definition - Jumbled mixture of tissue native to

the site / organ• Eg: Hamartoma of lung

Choristoma• Definition – Normal organized tissue at an abnormal site (ectopic rest

of normal tissue)• Eg: adrenal cells under kidney capsule, pancreas in stomach

A wrong decisionJohannes Fibiger Nobel prize winner in 1926

Katsusaburo Yamagiwa

In 1915 Drs. Koichi Ichikawa and Katsusaburo Yamagiwa of the Hokkaido University, Japan painted coal tar on the ears of 101 rabbits every 2 or 3 days.

In 1775, Dr. Percivall Pott, a British surgeon, reported one of the earliest observations on

environmental / occupational cancer

Two common cancers in our country

in India, cancers of lung and mouth in men and cervix and breast in women are the biggest killers

neoplasia introduction

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