Malignant

In medicine, the word malignant is commonly used to describe a cancerous growth of cells. For example, pathologists use the term malignant neoplasm to describe a cancerous tumour. Malignant can also describe serious or life-threatening non-cancerous conditions. Dangerously high blood pressure is called malignant hypertension, and dangerously high internal body temperature is called malignant hyperthermia. The opposite of malignant is benign, which means non-cancerous and generally non-life-threatening.

Features of malignant tumours

A tumour is considered malignant when the cells within it have developed the ability to:

• Grow uncontrollably.
• Damage or destroy surrounding normal tissue.
• Spread to other parts of the body (a process called metastasis).

Malignant tumours can begin in any part of the body. Their behaviour depends on several factors, including:

• The type of tumour.
• The size of the tumour.
• The grade of the tumour, which describes how abnormal the cells look under the microscope and how aggressively they are likely to behave.
• The amount of invasion, or how deeply the tumour has grown into the surrounding normal tissue.

Pathologists evaluate all these factors by examining the tumour tissue under a microscope. The results are included in your pathology report, which provides your doctor with detailed information about the tumour.

Not all malignant tumours behave the same way. Some are slow-growing and can often be cured with treatment. Others grow quickly, spread to distant parts of the body, and can be life-threatening. The information in the pathology report helps your doctor predict how the tumour will behave and select the most appropriate treatment. This prediction of tumour behaviour is referred to as prognosis.

Types of malignant tumours

There are many different types of malignant tumours, each with unique features. The type of tumour can only be determined by examining a tissue sample under a microscope. Here are some of the most common types:

• Squamous cell carcinoma: A cancer that develops from squamous cells, which are found in the skin, lining of the mouth, and other areas of the body.
• Adenocarcinoma: A cancer that arises from glandular cells, which are found in organs such as the stomach, colon, and breast.
• Melanoma: A cancer of melanocytes, the cells that produce pigment in the skin.
• Sarcoma: A cancer that starts in soft tissue such as bone, muscle, or fat.
• Lymphoma: A cancer of the lymphatic system, which is part of the body’s immune system.

Each type of malignant tumour has its own characteristics, treatment options, and prognosis. Understanding the type of tumour is an essential first step in planning the best treatment and care.