Download Epidemiology 242: Cancer Epidemiology

Epidemiology: Pathology Basis
of Caner
Lec-14
Lecturer: Dr. Twana A. Mustafa
What is the difference
between “tumor” vs
“cancer”
Tumor – Either benign or
malignant
Cancer – Usually malignant
CANCER HISTOLOGICAL TYPE
• Three Major Categories:
– Epithelial – “Carcinoma”
– Mesenchyme – “Sarcoma”
– Hematopoitic – “Leukemia/Lymphoma”
• Other Minor Categories:
– Nevocytic – “Melanoma”
– Germ cell – Teratoma, Seminoma, Yolk sac tumor,
Choriocarcinoma, etc…
– Endocrine/Neuro – Carcinoid/Insulinoma/small cell
carcinoma, etc…
CARCINOMA
• Squamous – Squamous Cell Carcinoma.
• Glandular - Adenocarcinoma.
• Transitional – Transitional Cell Carcinoma.
• Small cell – Small cell carcinoma
SARCOMA
• Muscle
– Smooth muscle: Leiomyosarcoma
– Skeletal muscle: Rhabdomyosarcoma
• Fat – Liposarcoma
• Skeleton – Osteosarcoma
• Cartilage – Chondrosarcoma
Carcinoma
• Carcinoma (Cancer of the epithelium) 85%
Epithelium is the term applied to the cells
that cover the external surface of the body
or that line the internal cavities, plus those
cells derived from the linings that form
glands.
Why most common cancers are
epithelial origin?
• These cells are the first point of contact of
the body with environmental substances,
either directly (squamous cells) or
indirectly (glandular cells).
• Epithelial cells usually have fast turn over
rate, i.e., fast cell division, and their DNA
can be damaged by carcinogens more
often than non-dividing cells.
Carcinoma: Squamous cell
• Originates from stratified squamous
epithelium of the skin, mouth, esophagus,
and vagina, as well as from areas of
squamous metaplasia, as in the bronchi or
squamocolumnar junction of the uterine
cervix. SCC is marked by the production of
keratin.
Skin Cancer
Squamous Cell Carcinoma
Carcinoma, Transitional Cell
• Transitional cell carcinoma - arise from the
transitional cell epithelium of the urinary
tract, such as bladder.
transitional cell carcinoma of the urothelium is shown here at low power
to reveal the frond-like papillary projections of the tumor above the
surface to the left. It is differentiated enough to resemble urothelium, but
is a mass. No invasion to the right is seen at this point.
TCC at high power
Carcinoma: Adenocarcinoma
• Adenocarcinoma - is carcinoma of
glandular epithelium and includes
malignant tumors of the gastrointestinal
mucosa, endometrium, and pancreas; and
is often associated with desmoplasia,
tumor-induced proliferation of nonneoplastic fibrous connective tissue,
particularly in adenocarcinoma of the
breast, pancreas, and prostate.
Prostate Ca
Ovarian Ca
Sarcoma
• Sarcoma is a malignant tumor of
mesenchymal origin
• Sarcoma is often used with a prefix that
denotes the tissue of origin of the tumor,
as in osteosarcoma (bone),
leiomyosarcoma (smooth muscle),
rhabdomyosarcoma (skeletal muscle), and
liposarcoma (fatty tissue).
Classification of tumor
according to stage
Classification of Tumor
according to its
differentiation (grade)
Gleason's breakthrough was to
develop a reproducible description
of the glandular architecture, to
which one assigns a score from 1
to 5. The pathologist looks for a
major pattern and a minor pattern
to give a Gleason sum between 2
and 10. On the left is a picture
adapted from Gleason's 1977
article demonstrating the changes
in gland pattern as one goes from
grade 1 to grade 5 cancer. The
glands in grade 1 cancer are small
and round. Grade 5 cancer is
hardly forming glands at all.
Gleason Grade 1 Prostate Cancer
At right is Gleason 3 CaP.
The glands are irregularly
shaped. They are mixed in
with some normal glands.
This tumor is infiltrating
the prostate.
At higher
magnification, there
are nests of glands with
no intervening stroma.
This is characteristic of
higher grade CaP
Here is Gleason 5,
or poorly
differentiated
cancer. You can see
that it is invading
the seminal vesicle
(stage T4)
The cells are not
organized into glands,
but are infiltrating the
prostate as cords.
Thank You!