Dr. Ananda Dyuti Hira
Neoplasia means “new growth” and a new
growth is called a neoplasm.
Oncology (Greek oncos = tumor) is the study
of tumors or neoplasms.
According to British eminent Oncologist, Sir
Rupert Willis “A neoplasm is an abnormal
mass of tissue, the growth of which exceeds
and is uncoordinated with that of the normal
tissues and persists in the same excessive
manner after cessation of the stimuli which
evoked the change”.
Classification of tumor
Tumor may be classified as-
1) Naked eye appearance
2) Histogenetic(including embryological
• Naked eye appearance-
-Schirrhous(hard due tolarge amounts of
• Histogenetic classification-
1) Tumors of epithelial origin(e.g squamous
2) Tumors of connective tissue origin(fibroma,
4) Latent cancer
5) Dormant cancer
6) Carcinoma in situ
7) Spontaneous regressions
• A tumor is said to be benign when its
microscopic and gross characteristics are
considered relatively innocent, implying that it
will remain localized, it cannot spread to other
sites, and it is generally amenable to local
surgical removal; the patient generally
e.g papilloma, adenoma, fibroma, lipoma,
osteoma, chondroma, leiomyoma.
Adenoma : Benign epithelial neoplasm derived
from glands, although they may or may not
form glandular structures.
Malignant tumors are collectively referred to as
cancers, derived from the Latin word for crab,
because they adhere to any part that they seize
on in an obstinate manner, similar to a crab.
Malignant, as applied to a neoplasm, implies that
the lesion can invade and destroy adjacent
structures and spread to distant sites
(metastasize) to cause death. Not all cancers
pursue so deadly a course. Some are discovered
early and are treated successfully, but the
designation malignant always raises a red flag.
Locally malignant tumor/ tumors of
These tumors do not fit either into benign/
malignant group. These are locally invasive
tumor but show little/ no tendency to
e.g Basal cell carcinoma, Ameloblastoma,
carcinoid tumor, Giant cell tumor,
pleomorphic tumor of salivary gland.
• Carcinoma in situ- preinvasive proliferation of
the epithelium that has cytological features of
• All tumors, benign and malignant, have two
basic components: (1) clonal neoplastic cells
that constitute their parenchyma and (2)
reactive stroma made up of connective tissue,
blood vessels, and variable numbers of
macrophages and lymphocytes.
• Mixed tumor- more than one neoplastic cell
usually derived from one germ layer.
e.g.Pleomorphic adenoma of salivary gland,
fibroadenoma of breast.
Teratoma, which contains recognizable mature or
immature cells or tissues representative of more
than one germ cell layer and sometimes all three.
Originate from totipotential cells. Such
cells have the capacity to differentiate into any of
the cell types found in the adult body.
Benign (mature) teratoma : When all the
component parts are well differentiated,
Malignant teratoma: It is when less well
differentiated, it is an immature, potentially or
FIGURE: A, Gross appearance of an opened cystic teratoma of the ovary. Note the presence of hair, sebaceous
material, and tooth. B, A microscopic view of a similar tumor shows skin, sebaceous glands, fat cells, and a tract
of neural tissue (arrow).
Characteristics of Benign & Malignant
DIFFERENTIATION AND ANAPLASIA
Differentiation: Extent to which neoplastic
parenchymal cells resemble the corresponding normal
parenchymal cells, both morphologically and
Anaplasia: Lack of differentiation.
Pleomorphism - variation in size and shape.
Abnormal nuclear morphology -the nuclei
contain abundant chromatin and are dark staining
- Nuclear-to-cytoplasm ratio may
approach 1 : 1 instead of the normal 1 : 4 or 1 : 6.
Nuclear shape is variable and often irregular, and
the chromatin is often coarsely clumped and
distributed along the nuclear membrane.
- Large nucleoli are usually present in
- Mitoses - large numbers of mitoses,
reflecting the higher proliferative activity of the
parenchymal cells,atypical, bizarre mitotic figures,
sometimes producing tripolar, quadripolar, or
• - Loss of polarity- Sheets or large masses of
tumor cells grow in an anarchic, disorganized
• - Other changes- formation of tumor giant
cells, some possessing only a single huge
polymorphic nucleus and others having two or
more large, hyperchromatic nuclei.
FIGURE : Anaplastic tumor of the skeletal muscle (rhabdomyosarcoma). Note the
marked cellular and nuclear pleomorphism, hyperchromatic nuclei, and tumor giant
cells). Note thpleomorphis nuclei, and tumor giant cells.
FIGURE : Anaplastic tumor showing cellular and nuclear variation in size and shape. The
prominent cell in the center field has an abnormal tripolar spindle.
Comparisons between Benign and
• Local invasion
Differentiation / anaplasia
Rate of growth
• METASTASIS - Metastases are tumor implants
discontinuous with the primary tumor.
Pathways of Spread
Dissemination of cancers may occur through
one of three pathways:
(1) direct seeding of body cavities or surfaces,
Sometimes mucus-secreting appendiceal carcinomas fill the
peritoneal cavity with a gelatinous neoplastic mass referred to
as pseudomyxoma peritonei.
(2) lymphatic spread,- most common pathway for
the initial dissemination of carcinomas.
(3) hematogenous spread - Typical of sarcomas but
is also seen with carcinomas. liver and lungs are most
frequently involved in such hematogenous dissemination.
Skip metastasis : Local lymph nodes, however,
may be bypassed because of venous-
lymphatic anastomoses or because
inflammation or radiation has obliterated
Sentinel lymph node : The first node in a
regional lymphatic basin that receives lymph
flow from the primary tumor.
• Oncogenes: Genes that promote autonomous
cell growth in cancer cells.
• Proto-oncogenes: Unmutated cellular
Carcinogenic Agents & Their Cellular
• Major Chemical Carcinogens
• DIRECT-ACTING CARCINOGENS
• Alkylating Agents
• Dimethyl sulfate
• Anticancer drugs (cyclophosphamide,
chlorambucil, nitrosoureas, and others
• Acylating Agents
• Dimethylcarbamyl chloride
Oncogenic RNA Viruses
Human T-Cell Leukemia Virus Type 1
HTLV-1 causes a form of T-cell
Oncogenic DNA Viruses
Human Papilloma virus
Hepatitis B and C Viruses
• Certain non-neoplastic disorders have a well-
defined association with cancer that they have
been termed precancerous conditions.
chronic atrophic gastritis of pernicious anemia,
solar keratosis of the skin,
chronic ulcerative colitis, and
leukoplakia of the oral cavity, vulva,
Clinical Aspects of Neoplasia
• Local and Hormonal Effects
• Cancer Cachexia
• Paraneoplastic Syndromes
• Paraneoplastic syndromes: Symptom
complexes in cancer-bearing individuals that
cannot readily be explained, either by the
local or distant spread of the tumor or by the
elaboration of hormones indigenous to the
tissue from which the tumor arose.
• Important to recognize, for several reasons:
• They may represent the earliest manifestation
of an occult neoplasm.
• In affected patients they may represent
significant clinical problems and may even be
• They may mimic metastatic disease and
therefore confound treatment.
Cushing syndrome Small-cell carcinoma
ACTH or ACTH-like
hormone or atrial
Hypercalcemia Squamous cell
carcinoma of lung
TGF-α, TNF, IL-1
• The major staging system currently in use is
the American Joint Committee on Cancer
Staging. This system uses a classification called
the TNM system. T for primary tumor, N for
regional lymph node involvement, and M for
LABORATORY DIAGNOSIS OF
1) Histological examination:
Biopsy: A mass or piece of tissue is removed
from the diseased organ for histopathological
examination. Biopsy are several types-
Excisional biopsy, Incisional Biopsy, Punch
Biopsy, core needle biopsy, Wedge biopsy,
Ultrasound/ CT guided Biopsy
Tumor markers are biochemical indicators of
the presence of a tumor. The include cell-
surface antigens, cytoplasmic proteins,
enzymes and hormones.
Importance/ utility of tumor marker
1) As a laboratory test to support the diagnosis.
2) In determining the response to therapy.
3) In indicating relapse during the follow up
Selected Tumor Markers
Calcitonin Medullary carcinoma of
α-Fetoprotein Liver cell cancer,
Prostatic acid phosphatase Prostate cancer
Neuron-specific enolase Small-cell cancer of lung,
Immunoglobulins Multiple myeloma and other
Prostate-specific antigen and
MUCINS AND OTHER
CA-125 Ovarian cancer
CA-19-9 Colon cancer, pancreatic cancer
CA-15-3 Breast cancer
NEW MOLECULAR MARKERS
p53, APC, RAS mutants in stool
p53 and RAS mutants in stool
p53 and RAS mutants in
sputum and serum