A neoplasm is an abnormal and excessive growth of tissue resulting from uncontrolled cell division. This growth process, called neoplasia, is uncoordinated with surrounding normal tissue and continues even if the initial trigger is removed. The resulting mass is often called a tumor, a term used for the physical swelling or lesion formed by the neoplasm. It is important to distinguish these terms from “cancer,” which specifically refers to malignant neoplasms.
Classifying Neoplasms
The primary classification of neoplasms divides them into benign and malignant categories based on their behavior. This distinction considers their growth rate, ability to invade nearby tissues, and potential to spread, which is fundamental to predicting a patient’s outcome.
Benign neoplasms are non-cancerous growths characterized by slow growth. They have well-defined borders and are often enclosed within a fibrous capsule. This encapsulation keeps the growth localized and prevents it from invading adjacent tissues. Because they do not spread to other parts of the body—a process known as metastasis—they are not considered life-threatening. However, a benign tumor can cause problems if it grows large enough to press on vital organs.
Malignant neoplasms, or cancers, exhibit more aggressive behavior. They grow rapidly and lack the well-defined capsules seen in benign tumors, which allows their cells to invade and destroy surrounding normal tissues. The defining characteristic of a malignant neoplasm is its ability to metastasize. Cancer cells can break away from the primary tumor, travel through the bloodstream or lymphatic system, and form new tumors in distant organs.
Neoplasm Development and Risk Factors
The formation of a neoplasm begins at the cellular level with changes to DNA, the molecule that contains the instructions for all cellular activities. Genes within the DNA act as regulators, telling cells when to divide and when to stop. When these genes sustain damage, or mutations, this control system can fail, leading to the uncontrolled cell proliferation that defines neoplasia. It requires multiple mutations in different genes over time for a cell to become cancerous.
Several factors contribute to the DNA mutations that can lead to neoplasms:
- Environmental exposures to carcinogens like those in tobacco smoke, asbestos, and pollutants.
- Physical agents such as ultraviolet (UV) radiation from the sun or tanning beds.
- Lifestyle choices, including a diet high in processed foods, obesity, excessive alcohol consumption, and a lack of physical activity.
- Infectious agents, such as the human papillomavirus (HPV) which is linked to cervical cancer, and hepatitis B and C viruses which can lead to liver cancer.
- Inherited genetic mutations from parents, such as in the BRCA1 and BRCA2 genes, which increase the risk for breast and ovarian cancers.
Diagnostic Processes
Diagnosing a neoplasm is a multi-step process that often begins with a physical examination and a review of a patient’s symptoms and medical history. If a neoplasm is suspected, the next step involves imaging tests to visualize internal structures and locate the potential mass.
X-rays and computed tomography (CT) scans use radiation to create detailed cross-sectional images, helping to identify a tumor’s size and location. Magnetic resonance imaging (MRI) uses magnetic fields to produce highly detailed images of soft tissues, useful for examining the brain or joints. A positron emission tomography (PET) scan can help determine if a tumor is malignant by using a radioactive tracer that accumulates in highly active cells. Blood tests may also be used to look for “tumor markers,” substances that can be elevated in the presence of cancer.
While imaging and blood tests can strongly suggest a neoplasm, a definitive diagnosis requires a biopsy. A biopsy is the removal of a small tissue sample from the suspicious area for microscopic examination by a pathologist. This analysis confirms if the cells are abnormal and determines whether the neoplasm is benign or malignant, which is necessary to plan treatment.
General Treatment Approaches
The treatment plan for a neoplasm is highly dependent on its classification as either benign or malignant, as well as its size, location, and the patient’s overall health. For benign neoplasms, treatment may not always be required. If a benign tumor is small and not causing symptoms, a strategy of “watchful waiting” or active surveillance may be adopted. Surgery to remove the tumor is the most common treatment if it is causing pain or pressing on organs.
Treatments for malignant neoplasms are more aggressive due to their invasive nature and potential to metastasize. Surgery is often a primary treatment, aimed at removing the entire cancerous tumor. Radiation therapy uses high-energy rays to target and destroy cancer cells, while chemotherapy involves using drugs that kill rapidly dividing cells throughout the body.
More specialized treatments have also become common. Targeted therapy uses drugs designed to attack specific vulnerabilities in cancer cells, often with fewer side effects than traditional chemotherapy. Immunotherapy is another approach that works by stimulating the patient’s own immune system to recognize and attack cancer cells. Often, a combination of these treatments is used to provide the most effective outcome.