Neoplasia: Understanding Tumor Growth

Neoplasia and Cancer Etiology

• Neoplasia refers to the process of abnormal and uncontrolled cell growth, leading to the formation of neoplasms or tumors.
• Cancer etiology includes several factors such as genetic predisposition, environmental influences, and infections that contribute to the development of cancer.

Neoplasm Classification

• The suffix commonly used to name neoplasms is "-oma."
• Malignant tumors are characterized by rapid growth, infiltration into surrounding tissues, and a tendency to recur.

Infection and Cancer

• H. pylori infection has been linked to stomach cancer.
• Human Papillomavirus (HPV) is associated with cervical cancer.

Tumor Characteristics

• Genes that regulate programmed cell death are known as apoptosis-regulatory genes.
• Malignant tumors exhibit uncontrolled growth patterns, with the presence of abnormal cells that show features like pleomorphism and high mitotic rates.

Benign vs. Malignant Neoplasms

• Benign neoplasms are typically well-circumscribed, localized, and have a favorable prognosis, while malignant neoplasms are invasive and associated with poor outcomes.
• The process of expansion and infiltration by malignant tumors is referred to as invasion.

Microscopic and Clinical Features

• The cut section of a malignant tumor may display features such as necrosis and irregular borders.
• Benign tumors often present as noncapsulated polyps, known as papillomas.
• Microscopic examination of malignant tumor cells reveals an abnormal morphology, including irregular nuclei and varied cell sizes.

Infectious Processes

• Bacterial infection is defined as the presence and multiplication of bacteria in the body, often causing disease.
• Direct transmission through skin or mucous membranes characterizes certain methods of infection.
• 'Subclinical infection' results in no apparent symptoms despite the presence of the pathogen.

Toxaemia and Bacteraemia

• Toxaemia denotes the presence of toxins in the blood, stemming from bacterial infections or metabolic processes.
• Bacteraemia is defined as the presence of bacteria in the bloodstream.
• The term for the severe circulation and multiplication of virulent microorganisms along with their toxins in the blood without localization is known as septicemia.

Tuberculosis

• The primary site affected by primary tuberculosis is typically the lungs.
• Adult tuberculosis generally results from reactivation of dormant foci or exogenous infections by Mycobacterium tuberculosis.
• Secondary tuberculosis can spread through natural passages, the bloodstream, or lymphatic system leading to wider infection.
• Predisposing factors for primary pulmonary tuberculosis include immunosuppression or malnutrition.

Primary Pulmonary Complex

• The primary pulmonary complex comprises the initial area of infection, regional lymph nodes, and the inflammatory response.
• The term for the reactivation leading to apical or subapical involvement in secondary pulmonary tuberculosis is known as reactivation tuberculosis.
• Tuberculous granulomas, or tubercles, exhibit caseation necrosis microscopically.

Causative Agent of Tuberculosis

• Mycobacterium tuberculosis is the primary bacillus responsible for causing tuberculosis in humans.

Learn about neoplasia, which refers to the abnormal growth of tissue that exceeds and is uncoordinated with normal tissue. This quiz covers the general features, origins, and classification of neoplasia.