RADIOSENSITIVITY OF TUMORS
RADIOSENSITIVITY OF TUMORS Tumors, like their cell of origin, differ in their susceptibility to radiation injury. In general, a poorly differentiated tumor is more radiosensitive than a well differentiated one of the same type. 1- Radio-sensitive tumours: Destructive dose of radiation_causes no significant damage in adjacent normal tissues. Examples Malignant lymphoma – Seminoma of testis […]
RADIATION EFFECTS ON DIFFERENT TISSUES
RADIATION EFFECTS ON DIFFERENT TISSUES Following a substantial dose of radiation, there is a latent interval of hours or days before histological evidence of tissue injury is seen. As already explained, the damage depends on: a- The dose b- Type of radiation c- The interval following exposure d- The tissue exposed. Skin A) […]
IONISING RADIATIONS
IONISING RADIATIONS Types of ionizing radiation: Electromagnetic radiation: X-rays and Gamma rays. Particulate radiation: alpha particles – beta particles – protons – electrons and neutrons. – All of these radiations can be administered to animals and human beings: Externally or Internally. External sources include X-ray machines, electron accelerators. Internal irradiation arises from the […]
Pictures Of Disturbance of growth and neoplasia
Pictures Of Disturbance of growth and neoplasia Fibroadenoma Squamous cell carcinoma Adenocarcinoma Chondroma Lipoma Leiomyoma Osteosarcoma Intradermal nevus Malignant melanoma
DIAGNOSIS OF TUMORS
DIAGNOSIS OF TUMORS The final diagnosis of any tumor is usually based on the histological examination using the following ways: Frozen section. Paraffin section. 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 […]
ETIOLOGY OF TUMORS
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: The hydrocarbons: the development of carcinoma of the scrotum in chimney sweepers was observed very […]
HAMARTOMA
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
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. […]
TERATOMA
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 […]
TUMORS OF PIGMENTED CELLS
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: Junctional nevus: appears as a flat brown lesion in […]