25. The following figure shows how cancer cases have
been progressively increasing from 2004 to 2010
26. 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
28. 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)
30. 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
31. 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
34. Desmoplasia
Formation of abundant collagenous stroma
Stimulated by parenchymal cells
• Ex: Schirrous. ca of breast Linitus plastica
(ca stomach) Carcinoma prostate
38. 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
45. Placental epithelium Hydatidiform mole Choriocarcinoma
Testicular epithelium
(germ cells)
Seminoma
Melanocytic Tumors Nevus
Embryonal carcinoma
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
46. Tissues with NO benign tumors
Synovium
Mesothelium
Lymphoid tissue
Hematopoietic cells
Basal cells of skin or adnexa
47. 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”
50. Neoplasms of Embryonic
Pluripotent Cells
Pluripotent cells can mature into several
different cell types
These neoplasms are generally called
Embryomas or Blastomas
51. Blastoma
All blastomas are childhood tumors
All blastomas are malignant tumors
Except:
Chondroblastoma
Osteoblastoma
Pulmonary blastoma
54. Exceptions to These Rules
Neoplasms That Sound Benign But Are
Really Malignant
Neoplasms That Sound Malignant But Are
Really Benign
Leukemias
Mixed Tumors
Whose Cell
o
f Origin Is
Neoplasms
Unknown
Lymphoma
Plasmacytoma
Melanoma
Glioma
Astrocytoma
Osteoblastoma
Chondroblastoma
55. 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
56. Mixed tumor
Tumors with single type of
parenchymal cells that differentiates
into many cell lines
–Eg: Pleomorphic adenoma of
salivary gland.
58. 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
59. What are the common sites for teratomas ?
Gonads
Mid line
Lines of fusion
69. 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.
71. Hamartoma
• Definition - Jumbled mixture of tissue native to
the site / organ
• Eg: Hamartoma of lung
72. Choristoma
•
•
Definition – Normal organized tissue at an abnormal
site (ectopic rest of normal tissue)
Eg: adrenal cells under kidney capsule, pancreas in
stomach
74. 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.
75. In 1775, Dr. Percivall Pott, a British surgeon,
reported one of the earliest observations on
environmental / occupational cancer
76. 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
