Category Archives: Disturbance of growth and neoplasia

Pictures Of Disturbance of growth and neoplasia

Posted by on February 3, 2012 No comments

Pictures Of Disturbance of growth and neoplasia

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Fibroadenoma

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Squamous cell carcinoma

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Adenocarcinoma

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Chondroma Lipoma

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Leiomyoma

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Osteosarcoma

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Intradermal nevus

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Malignant melanoma

DIAGNOSIS OF TUMORS

Posted by on February 3, 2012 No comments

DIAGNOSIS OF TUMORS

 

The final diagnosis of any tumor is usually based on the histological examination using the following ways:

  1. Frozen section.
  2. Paraffin section.
    1. Exfoliative cytology (based on the fact that the tumor cells are shed off and appear in exudates and secretions.

    4. Tumor markers: These are markers present in blood or tissues in case of tumor and are used for diagnosis and follow up.


     

ETIOLOGY OF TUMORS

Posted by on February 3, 2012 No comments

ETIOLOGY OF TUMORS

 

The actual cause of tumors remains obscure up till now. However many pre-disposing factors known as carcinogenic agents, appear to play a certain role in the development of certain tumor.

These factors are:

1) Chemical carcinogens:

  1. The hydrocarbons: the development of carcinoma of the scrotum in chimney sweepers was observed very early. Experimentally carcinoma of the skin of the ear of the rabbit can be induced by painting tar daily for 6 months.
  2. The aromatic amines: as aniline, benzidine. Carcinoma of urinary bladder is observed in laborers working with aniline dyes.
  3. Heavy cigarette smoking has direct relation with development of carcinoma of lung and urinary bladder.
  4. High incidence of mesothelioma (a malignant tumor of pleura) is found in laborers working in contact with asbestos.

 

2- Physical agents:

a) Ionizing radiation: usually leads to the development of carcinoma of the skin, leukemia, and osteogenic sarcoma.

 

  1. The continuous exposure of the skin to the ultraviolet rays of sunshine may lead to basal cell carcinoma and squamou cell carcinoma.
  2. Heat: it was shown that an increased incidence of carcinoma of the lip occurs in pipe smokers, but the action of tobacco may be added to the effect of heat.

 

3-    Hormones: THE sex hormones are considered as
carcinogenic agents and carcinoma of the breast in
mice can be produced by administration of large
doses of estrogen. There are some tumors which
depend in their growth on hormones and are known
as hormone dependant tumors such as:

b- Carcinoma of the prostate: is stimulated by androgen and its growth can be arrested by administration of estrogen.

c- Carcinoma of the breast: depends on its growth estrogen and prolactin. Removal of both ovaries may lead to arrest of growth of this tumor.

 

  1. Benign tumors: may be followed by malignant transformation such as villous papilloma of the urinary bladder and duct papilloma of the breast.

 

  1. Chronic inflammation:

    d- Urinary bilharziasis: usually predisposes to carcinoma of the urinary bladder (squamous metaplasia).

    e- Squamous cell carcinoma may develop in the edge of a chronic ulcer of the skin.

    f- Chronic gastric ulcers are precancers lesions.

     

     

     

    6- Viruses and tumors: virus infection as an etiological factor in tumor formation is now becoming more and more popular. (It may induce certain changes in the genetic material of the affected cells rendering them capable of division and proliferation). Recently a true virus (the plyoma virus) was isolated from leukaemic mice, which in turn produced leukemia when injected into healthy mice.

    Three classes of genes are target for genetic change which result in the formation of tumors:

    1. Growth promoting genes (proto-oncogenes) which when change to oncogenes become tumorogenic.
  2. Cancer suppressor genes
  3. Genes regulating apoptosis.

    Any disturbance in the balance between these genes may result in tumorogenesis.

HAMARTOMA

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HAMARTOMA

 

 

Hamartion: fault in development.

It is a tumor like mass which is formed due to developmental error and consists of the normal tissues of the part from which it arises but is irregularly arranged.

EMBRYONIC TUMORS

Posted by on February 2, 2012 No comments

EMBRYONIC TUMORS

 

 

These are usually malignant tumors which arise in children and are formed of malignant cells that resemble the embryonic cells which are initially present in the particular part of the body from which the tumor arises.

These tumors are:

  • Nephroblastoma (Wilm’s tumor) in kidney.
  • Neuroblastoma in adrenal medulla.
  • Medulloblastoma in cerebellum.
  • Retinoblastoma in Retina.

TERATOMA

Posted by on February 2, 2012 No comments

TERATOMA

 

Is a tumor which contains multiple types of tissue related to the three germinal layers i.e. ectoderm, mesoderm, endoderm, and are usually foreign to the part in which it arises.

Sites: the commonest site is the ovary. Types:

1-    Benign teratoma: More common and may be:

a- Solid.

b- Cystic (dermoid cyst): It contains hair, bone, cartilage etc..

2-    Malignant teratoma: (rare) It usually shows a mixture
tissues one of which shows malignant change of
squamous cell carcinoma or adenocarcinoma, or may
contain immature tissues.

Origin of teratoma:

Many theories were put to explain the origin of teratoma. The most accepted one is that it arises from foci of totipotent embryonic cells which are capable of division into many types of cells related to the three germinal layers.

TUMORS OF PIGMENTED CELLS

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TUMORS OF PIGMENTED CELLS

 

Nevus or pigmented mole:

It is a benign tumor of melanocytes of the skin of the face, neck and chest. It is present in nearly everyone and usually dates since birth and so now it is considered as hamartomatous malformation.

Types:

  1. Junctional nevus: appears as a flat brown lesion in which the pigmented cells are present deep in the epidermis and in upper dermis. It is the only type which may rarely turn malignant.
  2. Intradermal nevus: This appears as papillomatous or pedunculated deep brown lesion, in which pigmented cells are in the upper dermis only.
  3. Compound nevus: appears as elevated deep brown lesion having the microscopic picture of both types described above.

 

Malignant melanoma:

It is a highly malignant tumor which arises from the following sites:

1 – Skin either in a pre-existing nevus or more commonly arising directly from the melanocytes.

  1. Pigmented cells of the eye especially the choroid.
  2. Mucous membrane of the rectum, mouth cavity.

Gross appearance: It forms a rapidly growing ulcerated deep brown tumor, which infiltrates the surrounding tissues.

Microscopically: There is infiltration by masses of cuboidal or fusiform malignant cells, having darkly stained nuclei and many mitotic figures. Intra and extra cellular deep brown granules of melanin pigment are usually seen.

TUMORS OF VESSELS

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TUMORS OF VESSELS

 

  1. Benign
  1. Hemangioma: It is a benign tumor of blood vessels.
    It appears since birth and it is now considered as
    hamartomatous malformation.

It is of two types:

a)    Capillary hemangioma: This usually appears in the
skin as irregular red patch, not raised above the level
of skin.

Microscopically: It is formed of numerous small capillary-like blood spaces, filled with blood and separated by fibrous stroma.

b)    Cavernous hemangioma: This usually appears as
ill-defined, soft purple swelling, arising more
commonly in the following sites:

  • Skin especially that of the face.
    • Lips and tongue leading to macrocheilia and macroglossia respectively.
  • Internal organs, particularly the liver.

    2-    Cavernous lymphangioma: it is a benign tumor of
    lymph vessels, which is also considered now as a
    hamartomatous malformation. It usually appears in
    children as soft cystic swelling in the anterior triangle
    of the neck, where it is called cystic hygroma.

    Microscopically: It consists of numerous large irregular spaces lined by endothelial cells filled with lymph. The spaces are separated by fibrous stroma, containing multiple collections of lymphocytes.

 

2- Malignant:

  1. Hemangioendothelioma. Rare (skin, liver).
    1. Hemangiopericytoma. Rare tumor of pericytes which surround blood vessels.
    2. Hemangioarcoma: known as Kaposi sarcoma idiopathic hemorrhagic sarcoma: An uncommon tumor, it appears as multiple firm bluish subcutaneous nodules in the limbs, rarely in the buccal mucosa and some internal organs.

MALIGNANT MESENCHYMAL TUMORS

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MALIGNANT MESENCHYMAL TUMORS

 

 

Sarcoma:

- It is a malignant tumor arising from mesodermal tissues as connective tissues, muscles and lymphoid tissues.

Classification of sarcoma

I-    Cytological classification:

i.e. according to the shape and form of the sarcoma cells. It is only used in highly undifferentiated sarcomata where their origin cannot be definitely known from morphology.

These types are:

  1. Round cell sarcoma.
  2. Spindle cell sarcoma.
  3. Giant cell sarcoma.

II-    Histological classification:

i.e. according to the tissue of origin. This is a better classification and it is applied for differentiated types of sarcomata such as:

a) Fibrosarcoma: It is a malignant tumor arising from fibroblasts.

Microscopically: There are many large fusiform cells with pleomorphism. The stroma is formed of dense vascular collagenous bundles.

  1. Liposarcoma: A rare malignant tumor arising form fatty tissues, particularly in the retroperitoneal region and subcutaneous tissue of the thigh.
  2. Osteosarcoma or osteogenic sarcoma: It is a malignant tumor arising from osteoblasts.

Chondrosarcoma: It is a malignant tumor arising from bone and cartilage.

TUMORS OF MUSCLE

Posted by on February 2, 2012 No comments

TUMORS OF MUSCLE

 

I-    Benign:

  1. Leiomyoma: it is a benign tumor of smooth muscles. The commonest site is uterus where it is some times called “fibromyoma”, less common it occurs in the stomach and intestine.
  2. Rhabdomyoma: it is a rare benign tumor of striated muscles.

II-    Malignant:

In the form of sarcoma e.g. leiomyosarcoma, rhabdomyosarcoma.