Oncogenesis. Epithelial tumors....1. Epithelial tumours without specific localisation...

Oncogenesis. Epithelial tumors.

PhD, Ass. prof. B. Fylenko

Tumor (neoplasm, blastoma) is a pathological process characterized by autonomous, uncontrolled, unlimited tissue growth (cell multiplication).

The study of the tumors is called oncology (from oncos – tumor, and logos – study of).

The aetiology of tumours • Virogenetic Theory. It states integration of the

genomes of the virus into the normal cell which turns into a tumour cell.

• Physicochemical theory .suggests that tumour appears under the influence of different physical and chemical substances, so-called carcinogens.

• Dysontogenetic theory. According to his theory, tumours appear from the embryonic tissue and abnormally developed tissues under the influence of different causative agents.

• Polyetiological theory emphasises the importance of different factors, i. e. chemical, physical, viral, parasitic, dyshormonal.

The appearance of the tumour is various. Its shape may resemble a node, a mushroom cap or cauliflower a saucer.

Its surface may be smooth, bumpy, papillary. The tumour may grow as a node with distinct borders, it may have a limb or a capsule.

Secondary changes in the tumour result from disturbances of blood circulation in it as well as from chemo- or radiotherapy. They manifest by foci of necrosis, haemorrhages, inflammation, formation of mucus, calcification.

Macroscopically

The size of the tumour can be different. Its consistency depends on prevalence of parenchyma or stroma in it. It may be either soft

or solid (dense).

Types of tumors growth

expansive

infiltrating (invasive)

appositional

• At expansive growth the tumour grows from itself moving away the surrounding tissues. This type of growth is slow and is characteristic of benign tumours.

• Apposition growth is due to transformation of normal cells to tumour ones.

• In infiltrating growth, the cells of the tumour invade normal tissues and destroy them (so-called destructive growth).

Tumour growth in relation to the lumen of a hollow organ

• Endophytic growth is infiltrating growth of the tumour deep into the wall of the organ.

• Exophytic growth is expansive growth of the tumour to the cavity of the organ.

Atypism Atypism is the features of the cells and tissue that distinguish them from the normal cells.

The concept of atypism concerns the structure,

• metabolism,

• function,

• antigenic features,

• reproduction,

• differentiation.

The morphological atypism of tumour may be

tissue

cellular

Tissue atypism Tissue atypism is characterised by disturbance of tissue relationships typical for the organ. It is the violation of the shape and size of epithelial structures; the relationship of the parenchyma and stroma of epithelial tumours; different thickness of the fibrous (connective tissue, smooth muscle and others) structures, their chaotic location in tumours of mesenchymal origin.

Cellular atypism

• polymorphism or monomorphism of cells, nuclei and nucleoli,

• hyperchromia of nuclei, polyploidy, • change of the nuclear-to-cytonlasmic ratio, • appearance of numerous and distinctly atypical mitoses

METASTASIS is separation of tumour cells from the bulk and their transportation to other organs.

Metastatic pathways:

1) lymphogenic

2) haematogenic

3) implantation (contact)

4) mixed

Metastasis of adenocarcinoma into the lymph node H&E Staining

lymphogenic METASTASIS are carried through the lymphatic vessels to regional lymph nodes)

(забарвлення гематоксиліном і еозином)

Haematogenic metastases

haematogenic METASTASIS are carried with the blood flow to distant organs),

Implantation (contact) metastases

implantation METASTASIS when the tumour disseminates through the serous layers (peritoneum, pleura) and grow to the adjacent organs)

According to their clinico-morphological characteristics the tumors are divided into 3 groups:

• 1) benign,

• 2) malignant,

• 3) tumors with local destructive growth.

Benign tumours are characterised by:

• tissue atypism,

• expansive growth,

• the tumour does not usually influence the body in general,

• the tumour does not produce metastases,

• relapses are rare.

Characteristics of malignant tumors

• tissue, cellular, biochemical, histochemical and antigenic atypism

• infiltrating (invasive) growth

• malignant tumours produce metastases

• malignant tumours often relapse

• malignant tumours produce local and general effect on the body

The tumours with local destructive growth occupy the intermediate place between benign and malignant. They have the features of infiltrating growth but do not give metastases.

The classification was suggested as an international one by the Committee on Tumour Nomenclature of the International Anticancer Union.

Groups of tumours:

1. Epithelial tumours without specific localisation (non-organ-specific).

2. Tumours of the endocrine and exocrine glands as well as epithelial integument

(organ-specific).

3. Mesenchymal tumours.

4. Tumours of the melanin-forming tissue.

5. Tumours of the nervous system and brain membranes.

6. Tumours of the blood system.

7. Teratomas.

Classification of epithelial tumors • non-organ-specific – еpithelial tumours without

specific localisation.

• organ-specific – tumours of the endocrine and exocrine glands as well as epithelial integument

Depending on histogenesis:

from integumentary epithelium

From glandular epithelium

According to morphology:

bening

malignant

Benign epithelial non-organ-specific tumors

papillomas is a tumor originating from the skin and mucous membranes

Papilloma H&E Staining

The base of the tumor consists of connective tissue containing blood vessels. It is a continuation of subepithelial connective tissue covered with stratified squamous epithelium with increased number of layers.

Benign epithelial non-organ-specific tumors

Adenoma is a benign epithelial tumor from the epithelium of the glands and glandular organs.

Adenoma of the small intestine H&E Staining

The tumor is built up of complexes, resembling acinar (secretory) portions of glands, without signs of cellular atypism separated by layers of connective tissue.

Malignant tumors of epithelium Immature, or malignant, tumors of epithelium are also called cancers.

The term came to us from the time of Hippocrates and Galen.

According to differentiation of the tumor cells all cancers can be divided into 3 groups:

• well-differentiated: squamous-cell, with keratinization, without keratinization, adenocarcinoma (trabecular, alveolar, papillary, mucous);

• poorly-differentiated: small-cell or basal cell, medullar, scirrhus, solid;

• special kinds: chorionepithelioma, seminoma, hypernephroid cancer.

Cancer in situ Cancer in situ (carcinoma in situ) is an intraepithelial, non-invasive carcinoma.

atypical epithelium loses its polarity and complexity, the presence of pathological mitoses; tumor growth within the epithelial layer without passing into the underlying tissue (does not destroy the basement membrane).

Squamous cell carcinoma Squamous cell carcinoma is a malignant tumor originating from the squamous epithelium.

Localization: skin, mouth, lips, tongue, cervix, vagina, etc.), or on the mucous membranes covered by a single-layer epithelium after a previous squamous cell.

Squamous cell carcinoma

Adenocarcinoma • Adenocarcinoma (from Latin. Aden - cancer, cancer -

cancer) - malignant tumor from the glandular epithelium.

• Localization: gastrointestinal tract, respiratory tract, uterus, mammary gland, ovary.

Adenocarcinoma

The tumor is represented by glandular complexes of various forms and dimensions, which are formed by polymorphic epithelial cells with hyperchromic nuclei and figures of pathological mitoses (cellular atypism).

Mucous (colloidal) cancer Mucous (colloidal) cancer is an adenogenic cancer characterized by morphological and functional atypism.

• Macroscopically: colloidal or mucous masses.

• Microscopically: adenogenic atypical cells are among the mucus.

Solid (trabecular) cancer From Latin. Solidus - simple Microscopically: complexes of cancer cells with marked atypism and a large number of pathological mitoses, located in the form of trabeculae, delimited by connective tissue layers.

Small cell cancer Microscopically: monomorphic (lymphocytic) atypical cells with rounded nuclei and a narrow rim of the cytoplasm, many mitoses, areas of necrosis are among the small amount of stroma.

scirrhous cancer Fibrous cancer (scirrhous cancer) (from Greek. Scirros - dense) - undifferentiated carcinoma, characterized by the predominance of stroma over the parenchyma. Microscopic: chains of atypical polymorphic cells with hyperchromic nuclei located among well-developed coarse fibrous connective tissue.

Medullary (adenogenic) cancer • Medullary cancer is an undifferentiated carcinoma

characterized by a predominance of the parenchyma over the stroma.

• Microscopically: layers of atypical epithelium with pathological mitoses and a small amount of connective tissue, areas of necrosis.

Basal cell carcinoma • Basalioma (basal cell carcinoma) is a skin tumor characterized

by locally destructive growth and recurrence, but does not metastasize.

• Microscopic: small cells with a small amount of basophilic cytoplasm (dark cells), without intercellular junctions, located in cells or strands. Occasionally, skin-like appendages appear.

Examination of the oral mucosa revaled a small nodule with papillary surface. Histological examination revealed conjugate papillary proliferations of stratified squamous epithelium without cellular atypism and underlying stroma represented by thin-walled vessels and loose connective tissue. What formation has developed in a patient?

A. Fibroma

B. Papillomа

C. Fibrolipoma

D. Epithelium hyperplasia

E. Basal cell carcinoma

Microscopic examination of a skin tumor revealed that it invaded the underlying tissue, destroyed it and formed nests and cords of atypical epithelium which included some pearl-like formations. Specify the tumor:

A. Squamous cell non-keratinizing carcinoma

B. Keratinizing squamous cell carcinoma

C. Medullary carcinoma

D. Solid carcinoma

E. Adenocarcinoma

A 69-year-old male patient got a small plaque with subsequent ulceration on the skin of the lower eyelid. The formation was removed. Microscopic examination of dermis revealed complexes of atypical epithelial cells arranged perpendicularly to the basal membrane on the periphery. The cells were dark, of polygonal prismatic shape with hyperchromic nuclei with a high mitotic rate. What is the histological form of carcinoma in this patient?

A. Keratinizing squamous cell carcinoma

B. Nonkeratinizing squamous cell carcinoma

C. Adenocarcinoma

D. Basal cell carcinoma

E. Undifferentiated

Microscopy of colonic biopsy material revealed a tumour made up of prismatic epithelium and forming atypical glandular structures of various shapes and sizes. The basal membrane of glands was destroyed. Tumour cells were polymorphic, with hyperchromatic nuclei and a large number of pathological mitoses. What is the most likely diagnosis?

A. Basal cell carcinoma

B. Solid carcinoma

C. Adenocarcinoma

D. Mucosal carcinoma

E. Undifferentiated carcinoma

Histological study of the bronchial wall and adjacent lung segments revealed sheets and strands of squamous epithelium. The cells have moderately expressed symptoms of atypia: polymorphism, nuclear hyperchromatism, mitoses. In the center of the complex there are concentric pink formations. What is the most likely diagnosis?

A. Keratinizing squamous cell carcinoma

B. Non-keratinizing squamous cell carcinoma

C. Adenocarcinoma

D. Scirrhus

E. Undifferentiated carcinoma

A 57-year-old patient experiences periodical uterine haemorrhages. Diagnostic biopsy of lining of uterus has revealed among the blood elements some glandular complexes of different forms and sizes made by atypic cells having hyperchromic nuclei with multiple mitoses (including pathological ones). What is the most likely diagnosis?

A. Glandular endometrium hyperplasia

B. Uterus fibromyoma

C. Chorioepithelioma

D. Adenocarcinoma

E. Endometritis

A 46-year-old inveterate smoker has a white crateriform ulcer with dense edges in the right corner of mouth. Microscopical examination revealed cords of atypical multilayer epithelium ingrowing into the adjacent tissues and making clusters. In the centre of these clusters some roundish pink concentric formations can be seen. What is the most likely diagnosis?

A. Squamous cell nonkeratinous carcinoma

B. Keratinizing squamous cell carcinoma

C. Basal cell carcinoma

D. Adenocarcinoma

E. Leukoplakia

Histological examination of a microspecimen presenting a malignant lung tumour revealed that the tumor consisted of lymphocyte-like cells forming any structures. Stroma is mildely marked, there are a lot of mitoses and necroses. What tumour is it?

A. Fibroma

B. Adenocarcinoma

C. Small cell carcinoma

D. Squamous cell keratinous carcinoma

E. Squamous cell nonkeratinous carcinoma

Microscopical examination of a surgical specimen (an ulcered part of a lip) revealed in the connective tissue of mucous membrane near the borders and under the floor of the ulcer some epithelial complexes consisting of atypic multi-stratal epithelium with accumulations of bright pink concentric formations. What pathology is it?

A. Papilloma

B. Basal cell carcinoma

C. Transitional cell carcinoma

D. Squamous cell keratinous carcinoma

E. Squamous cell nonkeratinous carcinoma

A 19-year-old girl addressed an oncologist with complaints of slowly growing tumor-like mass on the tip of her tongue. The mass was first noticed 5-6 years ago. The patient requested no medical help. Objectively: there is a pale pink round growth with wide pedicle on the tongue apex; the growth is painless, elastic; there are no changes of mucosa surrounding the pedicle. Submandibular lymph nodes cannot be palpated. What kind of tumor is it?

A. Papilloma

B. Atheroma

C. Fibroma

D. Lipoma

E. Keratoma

Oncogenesis. Epithelial tumors....1. Epithelial tumours without specific localisation...

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