Malignant tumor

(noun)

In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the body through the lymphatic system or bloodstream.

Related Terms

Examples of Malignant tumor in the following topics:

  • Angiogenesis and Disease

    • It is also a fundamental step in the transition of tumors from a dormant state to a malignant one, leading to the use of angiogenesis inhibitors.
    • A malignant tumor consists of a population of rapidly-dividing and growing cancer cells.
    • Evidence now suggests the blood vessel in a given solid tumor may, in fact, be mosaic vessels, composed of endothelial cells and tumor cells.
    • This mosaicity allows for substantial shedding of tumor cells into the vasculature, possibly contributing to the appearance of circulating tumor cells in the peripheral blood of patients with malignancies.
    • As malignancy develops, cells progress from a prevascular stage (normal to early hyperplasia) to a vascular stage (late hyperplasia to dysplasia to invasive carcinoma).

  • Overview of Cancer

    • Cancer, known medically as a malignant neoplasm, is a broad group of various diseases, all involving unregulated cell growth.
    • Cancers comprise the malignant (having a tendency to become worse) subset of neoplasms—a cell or group of cells that undergo unregulated growth and form a mass of tissue—often referred to as a tumor.
    • Non-malignant tumors are referred to as benign; they are typically slower growing and are often surrounded by a membrane of connective tissue that prevents metatasis.
    • A common example of a benign tumor is a skin mole.
    • Malignant transformation can occur through the formation of novel oncogenes, the inappropriate over-expression of normal oncogenes, or by the under-expression or disabling of tumor suppressor genes.

  • Pancreatic Cancer

    • Pancreatic cancer is the uncontrolled growth of malignant cells in tissues forming the pancreas.The most common type is adenocarcinoma.
    • Pancreatic cancer is the uncontrolled growth of malignant cells in the tissues forming the pancreas.
    • The most common type, accounting for 95% of these tumors, is adenocarcinoma, which arises from the exocrine, or digestive, component of the pancreas .
    • The majority of pancreatic neuroendocrine tumors are histologically benign.
    • The treatment for these, as well as the less common malignant tumors, may include watchful waiting, surgery, hormone therapy, and radiation.

  • Testicular Cancer

    • Even for the relatively few cases in which malignant cancer has spread widely, modern chemotherapy offers a cure rate of at least 80%.
    • Not all lumps on the testicles are tumors, and not all tumors are malignant; there are many other conditions such as testicular microlithiasis, epididymal cysts, appendix testis (hydatid of Morgagni), and so on which may be painful but are non-cancerous.
    • Most of the remaining 5% are sex cord-gonadal stromal tumors derived from Leydig cells or Sertoli cells.
    • low back pain (lumbago) tumor spread to the lymph nodes along the back
    • About half of germ cell tumors of the testis are seminomas.

  • Cancer Immunology

    • Cancer immunology is the study of interactions between the immune system and cancer cells (also called tumors or malignancies).
    • Over the past several years there has been notable progress and an accumulation of scientific evidence for the concept of cancer immunosurveillance and immunoediting based on (i) protection against development of spontaneous and chemically-induced tumors in animal systems and (ii) identification of targets for immune recognition of human cancer.
    • Cancer immunotherapy attempts to stimulate the immune system to reject and destroy tumors.
    • Topical immunotherapy utilizes an immune enhancement cream (imiquimod) which is an interferon producer causing the patients own killer T cells to destroy warts, actinic keratoses, basal cell cancer, vaginal intraepithelial neoplasia, squamous cell cancer, cutaneous lymphoma, and superficial malignant melanoma.
    • Injection immunotherapy uses mumps, candida the HPV vaccine or trichophytin antigen injections to treat warts (HPV induced tumors).

  • Metastasis Through Lymphatic Vessels

    • Cancer occurs after a single cell in a tissue is progressively genetically damaged to produce a cancer stem cell possessing a malignant phenotype.
    • The newly formed "daughter" tumor in the adjacent site within the tissue is called a local metastasis.
    • Malignant cells can break away from the primary tumor and attach to and degrade proteins that make up the surrounding extracellular matrix (ECM).
    • The tumor cells are then transported to regional lymph nodes and ultimately, to other parts of the body.
    • Transcoelomic: The spread of a malignancy into body cavities can occur via seeding the surface of the peritoneal, pleural, pericardial, or subarachnoid spaces.

  • Brain Tumors

    • Brain tumors include all tumors inside the cranium or in the central spinal canal.
    • Brain tumors may also spread from cancers primarily located in other organs (metastatic tumors).
    • Visibility of signs and symptoms of brain tumors mainly depends on two factors: tumor size (volume) and tumor location.
    • The symptom onset—in the timeline of the development of the neoplasm—depends in many cases on the nature of the tumor but in many cases is also related to the change of the neoplasm from "benign" (i.e., slow-growing/late symptom onset) to more malignant (fast growing/early symptom onset).
    • Radiotherapy: the most commonly used treatment for brain tumors, the tumor is targeted with alpha and beta rays to shrink the tumor

  • Spinal Cord Compression

    • Spinal cord compression develops when the spinal cord is compressed by bone fragments from a vertebral fracture, a tumor, abscess, ruptured intervertebral disc, or other lesion .
    • The most common causes of cord compression are tumors, but abscesses and granulomas (e.g. in tuberculosis) are equally capable of producing the syndrome.
    • Emergency radiation therapy (usually 20 Gray in five fractions, 30 Gray in 10 fractions or eight Gray in one fraction) is the mainstay of treatment for malignant spinal cord compression.
    • Some tumors are highly sensitive to chemotherapy (e.g. lymphomas, small-cell lung cancer) and may be treated with chemotherapy alone.
    • The median survival of patients with metastatic spinal cord compression is about 12 weeks, reflecting the generally advanced nature of the underlying malignant disease.

  • Lymphomas

    • Typically, lymphoma is present as a solid tumor of lymphoid cells.
    • These malignant cells often originate in lymph nodes, presenting as an enlargement of the node (a tumor).
    • Lymphomas are closely related to lymphoid leukemias, which also originate in lymphocytes, but typically involve only circulating blood and bone marrow, and do not usually form static tumors (blood cells are generated in the bone marrow by a process termed haematopoesis).
    • Lymphoma is the most common form of hematological malignancy, or "blood cancer", in the developed world.

  • Skin Cancer

    • Skin cancers are abnormal growths of skin cells with varying degrees of malignancy.
    • Cancers of the epidermis exhibit varying degrees of malignancy.
    • Sometimes small blood vessels can be seen within the tumor.
    • Crusting and bleeding in the center of the tumor frequently develops.
    • Warning signs of malignant melanoma include change in the size, shape, color, or elevation of a mole.