Pathology

1. Neoplasia
Pathology Team

2. Define
eoplasia
Recognize
Differentiate
Neoplasm/
Neoplasia
Tumour Cancer
Hyperplasia
Metaplasia
Dysplasia
Classification
Growth
Ectoderm
Endoderm
Mesoderm
Tissue origin
Benign
Malignant
Risk factors
Epidemiology
Learning outcomes map

3. Session’s
Objectives
Lecture 1
By the end of this session students should be
able to:
◦ Identify neoplasia terminologies
◦ Recognize adaptive growth responses
◦ Provide classification of neoplasms
◦ Differentiate benign from malignant
neoplasms

4. Nomenclature
◦ Neoplasia means “new growth”: Neo….New, and Plasia…..Growth.
◦ Neoplasm is the collection of cells and stroma composing new growths.
◦ In the modern era, a neoplasm is defined as a genetic disorder of cell growth that is triggered by acquired or less
commonly inherited mutations affecting a single cell and its clonal progeny.
◦ Tumor originally described swelling caused by inflammation, but is now equated with neoplasm.
◦ Oncology (Greek oncos = tumor) is the study of tumors or neoplasms.

5. Terminology
Cancer (Latin word for crab): because the finger-like
spreading projections from a cancer called to mind the
shape of a crab.
Tumor is simply swelling:
-Inflammation
-Neoplasm

6. Neoplasm
“… is an abnormal mass of tissue, the growth of which exceeds and
is uncoordinated with that of normal tissues and persists in the
same excessive manner after cessation of the stimuli which invokes
the change. ”
Tumor cells’ growth is autonomous i.e. independent of
physiologic growth stimuli.

7. umor
Neoplastic Non-neoplastic
Monoclonal Polyclonal
Hyperplasia
Metaplasia
Dysplasia
Benign
Malignant

8. Tumors-related Non-Neoplastic lesions
Hamartoma: present as disorganized but benign-appearing masses
composed of cells indigenous to the particular site.
Choristoma: a congenital anomaly better described as a heterotopic nest of
cells
◦ Mature normal well-developed tissue at abnormal site, such as
Pancreatic tissue localized to submucosa of the stomach.

9. Literally means disordered growth.
Reversible replacement of one mature (DIFFERENTIATED) cell type
by Undifferentiated/ immature (cells of abnormal
sizes and shapes)
Characteristic features of dysplasia:
Often occurs in metaplastic epithelium
Disordered but non-neoplastic proliferation
Loss of uniformity
Pleomorphic and hyperchromatic nuclei
Mitoses more abundant than usual
No invasion of basement membrane.
If dysplasia is marked & involves entire thickness of
epithelium, it is considered as carcinoma in situ (pre-invasive stage of
cancer)
DYSPLASIA

11. Dysplasia:
Dysplasia can be precancerous but does not necessarily progress to cancer.
Changes that do not involve entire thickness of epithelium may be reversible, if the
cause is removed the epithelium may revert to normal.

13. Chronic Irritant
Growth factors
Dysplasia
Cancer

14. Classification of Neoplasms
◦ Based on clinical and biological behaviour:
Two main groups are recognized:
1. Benign.
2. Malignant.

15. Two broad categories of neoplasms on basis of pattern of growth
Neoplasms
Benign
Microscopic & macroscopic
characteristics are innocent, amenable
to surgical removal
1. Encapsulated
2. Slow-growing
3. Non-invasive
4. Remain localized
5. Well-differentiated
Malignant
Referred to as Cancer, can
invade & destroy adjacent
tissues & spread to distant sites.
1. Un-encapsulated
2. Fast-growing
3. Invasive
4. Metastasize
5. Well, moderate, and poorly-
differentiated/ anaplastic

16. Tumor structure
All tumors, benign and malignant, have two basic components:
1. Parenchyma:
◦ Made up of clonal/transformed neoplastic cells
◦ Resembles normal tissue (well- differentiated) in benign tumors
◦ In malignant neoplasms, neoplastic cells could be well differentiated, moderately
differentiated or poorly differentiated or pleomorphic (anaplastic)
2. Reactive stroma (Non-Neoplastic supporting tissues):
◦ Made up of connective tissue, blood vessels, and variable numbers of
macrophages and lymphocytes.
◦ Important for growth and evolution of neoplasms.
“Tumor nomenclature is based on parenchymal component”

17. Classification of Tumors based on cell of origin
1. Composed of one parenchymal cell type:
◦ Tumors of mesenchymal origin
◦ Tumors derived from endothelial and related tissues
◦ Tumors of epithelial origin
◦ Tumors of melanocytes
2. Composed of more than one neoplastic cell type, derived from
one germ cell layer
◦ Mixed tumors of salivary glands
3. Tumors composed of more than one neoplastic cell type, derived
from more than one germ cell layer-
◦ Teratoma

18. Neoplasm
◦ Tumours can arise from any cell
◦ Mesoderm
◦ Ectoderm
◦ Endoderm
◦ Benign
◦ Malignant

19. Neoplasm
Benign Malignant
Carcinoma
Sarcoma
Haemopoietic / lymphoid neoplasms
Melanoma
Germ cell tumors
Nomenclature
Ectoderm
Endoderm
Mesoderm

20. Neoplasm
Benign Malignant
Carcinoma Sarcoma
adenoma
angioma
Rhabdomyoma
lipoma
chondroma
Osteoma
leiomyoma
Nomenclature

21. Neoplasm
Benign Malignant
Carcinoma Sarcoma
Fibrosarcoma
Chondrosarcoma
leiomyosarcoma
Nomenclature
Mesenchymal
tissue

22. Neoplasm
Benign Malignant
Carcinoma Sarcoma
squamous cell carcinoma
adenocarcinoma,
Renal cell carcinoma
Nomenclature
Epithelial origin

23. Nomenclature
Benign Tumors
◦ The suffix “oma” is added to the cell type from which the tumor arises
BENIGN MESENCHYMAL TUMOURS
Fibroma
Chondroma
Leiomyoma & rhabdomyoma

24. Epithelial Tumors
Epithelium is derived from all three germ-cell layers
◦ Ectoderm – skin
◦ Endoderm – lining epithelium of GIT
◦ Mesoderm – renal tubular epithelium
So Mesoderm may give rise to carcinoma (epithelium) and sarcoma
(mesenchymal)

25. Nomenclature
Benign epithelial tumors
Adenoma
Papilloma
Polyp
Cystadenoma/ Papillary cystadenoma

26. Nomenclature of Malignant Tumors
◦ Malignant neoplasms of epithelial cell origin are called carcinomas
◦ Stratified squamous epithelium: squamous cell carcinoma
◦ Glandular pattern: Adenocarcinoma
◦ Placental epithelium: Choriocarcinoma
◦ Basal cells of skin : Basal cell carcinoma
◦ Urinary epithelium : Urothelial carcinoma (transitional cell carcinoma)
◦ Unknown tissue origin: Poorly diff. malignant tumor

27. Nomenclature of Malignant Tumors
◦ Malignant tumors arising from mesenchymal tissue are called sarcomas
◦ Fibrous tissue: fibrosarcoma
◦ Cartilage: chondrosarcoma
◦ Blood vessels: angiosarcoma
◦ Muscles: leiomyosarcoma & rhabdomyosarcoma

28. Mixed tumors of salivary glands
◦ Neoplastic cells are monoclonal but in some cases can show
divergent differentiation, creating mixed tumors in which both
epithelial & mesenchymal components(fibrous tissue, bones &
cartilage) are seen.
Tumors Derived from One Germ Cell Layer;

29. ◦ Tumors cells differentiating along more than one cell lineage, but
derived from one germ layer - MIXED TUMOURS
◦ Benign :
◦ Pleomorphic adenoma of salivary glands
◦ Fibroadenoma of breast
◦ Malignant:
◦ Malignant mixed tumor of salivary glands
◦ Phylloides tumor of the breast
◦ Wilms tumor of kidney
Nomenclature

30. Nomenclature
◦ Tumors comprising of more than one neoplastic cell type, derived from more than
one germ layer –Teratogenous
◦ TERATOMA
◦ Composed of multiple tissues foreign to the site of growth (bone, muscle, hair,
skin, brain)
◦ Arises in the gonads (testis or ovary) or in the midline of the body
◦ Benign: Mature teratoma (dermoid cyst)
◦ Malignant: Immature teratoma

31. Tumors Derived from More than One Germ Cell Layer
Teratoma of Ovary

32. Neoplasia Nomenclature
Malignant tumor
Benign tumor
Squamous cell carcinoma
Papilloma
Squamous epithelium
Adenocarcinoma
Adenoma
Glandular epithelium
Liposarcoma
Lipoma
Fat
Osteosarcoma
Osteoma
Bone
Rhabdomyosarcoma
Rhabdomyoma
Skeletal Muscle
(“… -oma’s” any growth )
examples : benign - malignant

33. Characteristics of Benign versus Malignant Tumors
Four fundamental rules by which benign tumors can be distinguished
from malignant tumors:
1. Differentiation & anaplasia
2. Rate of growth
3. Local invasion
4. Metastasis

34. Rules to differentiate benign from malignant tumors
1-Differentiation & Anaplasia
◦ Differentiation refers to the extent to which neoplastic parenchymal cells resemble the
corresponding normal parenchymal cells, both morphologically & functionally.
◦ Differentiation and anaplasia refers only to the parenchymal cells (i.e. tumor cells)
◦ Correlation with biologic behavior
◦ Benign tumors are well differentiated
◦ Malignant tumors can range from well to undifferentiated.
◦ Undifferentiated malignant tumors have no functional activity and worse
prognosis

35. Classification of tumor based on degree of
Differentiation
Well differentiated neoplasm
◦ Tumor cells resembles mature cells of tissue of origin
◦ Scanty mitoses
Moderately well differentiated neoplasm
◦ In-between the two extremes of well-diff. vs. un-diff. tumors
Undifferentiated or anaplastic tumor:
◦ Malignant neoplasms that are composed of poorly differentiated
cells are said to be anaplastic.

36. Anaplasia
Malignant neoplasm composed of undifferentiated cells are said to be
anaplastic
Anaplasia means loss of functional & structural differentiation
Marked pleomorphism
(variation in size & shape of cells)
Large & hyperchromatic nuclei
High nuclear to cytoplasmic ratio
Brisk mitoses
Giant cells
Loss of organization
Anaplasia is the hallmark of malignancy

37. Abnormal mitosis in an anaplastic cell