Cancer

Malignant tumors are cancerous and metastasize (spread to other tissues), causing damage.

• (A) Benign tumors are confined to one location.
• (C) Contact inhibition is lost in malignant cells (they grow uncontrollably).
• (D) Malignant tumors are neoplastic (abnormal cell growth).

Detecting cancers of internal organs relies heavily on imaging techniques that allow visualization of structures within the body. Let's examine the techniques listed:

• CT (Computed Tomography): This technique uses X-rays taken from multiple angles to create detailed cross-sectional images (slices) of internal organs, bones, soft tissue, and blood vessels. CT scans are widely used to detect tumors, assess their size and location, and check for spread (metastasis) in various internal organs like the lungs, liver, pancreas, kidneys, and abdomen. It is a very useful technique for detecting cancers of internal organs.
• MRI (Magnetic Resonance Imaging): This technique uses powerful magnetic fields and radio waves to generate highly detailed images of organs and soft tissues. MRI is particularly good at differentiating between different types of soft tissues and is often used to detect cancers in the brain, spinal cord, liver, prostate, uterus, and other areas. It does not involve ionizing radiation. It is also a very useful technique for detecting cancers of internal organs.
• Radiography (Conventional X-rays): This technique uses a small dose of ionizing radiation to create images of internal body structures. While standard X-rays are useful for detecting abnormalities in bones and the chest (e.g., lung cancer), they provide less detail of soft tissues compared to CT or MRI. Specialized radiography like mammography is crucial for breast cancer detection. Though sometimes less sensitive than CT or MRI for certain soft tissue tumors, radiography remains a useful tool in the detection and diagnosis process for some internal organ cancers (e.g., initial chest X-ray for lung issues).

Since CT, MRI, and Radiography are all established and useful techniques employed in the detection of cancers affecting internal organs (with varying applications and sensitivities depending on the specific cancer type and location), all the listed options are valid.

Therefore, the correct answer is All of the above.

Malignant tumors, commonly known as cancers, exhibit several properties that distinguish them from benign tumors and normal tissues. Let's analyze the given options:

• Neoplasty (or Neoplasia): This simply means "new growth" and refers to the formation of a neoplasm or tumor. Both benign and malignant tumors are neoplasms. While uncontrolled growth is a hallmark of cancer, neoplasia itself isn't the most feared property specific to malignancy.
• Metastasis: This is the process by which cancer cells break away from the primary tumor, enter the bloodstream or lymphatic system, travel to distant parts of the body, and form secondary tumors (metastases). This ability to spread makes the cancer systemic and significantly harder to treat effectively. Cancers that have metastasized are often associated with a poorer prognosis and higher mortality.
• Rapid invasive growth: Malignant tumors often grow rapidly and invade (infiltrate) surrounding tissues. This local invasion can damage nearby organs and structures and makes complete surgical removal difficult. While dangerous, a locally invasive tumor might still be treatable if it hasn't spread distantly.
• Loss of contact inhibition: Normal cells typically stop dividing when they come into contact with neighboring cells. Cancer cells lose this property, allowing them to continue dividing and pile up, contributing to tumor formation. This is a fundamental characteristic of uncontrolled cell growth but doesn't directly describe the spread or lethality associated with advanced cancer.

Comparing these properties, metastasis is widely considered the most feared property of malignant tumors. It is the primary cause of cancer-related death, as widespread secondary tumors are very difficult to eradicate completely with current therapies like surgery, radiation, or chemotherapy. The ability to spread throughout the body makes cancer a systemic disease, rather than just a localized problem.