Neoplasms

Neoplasms are a mass of abnormal tissue whose growth is excessive and uncoordinated compared to normal tissue and persists in the same way after the cessation of the stimulus that caused it. Neoplasms can be divided into two broad categories: benign and malignant. The neoplasm is generally known as cancer . Most neoplasms manifest macroscopically by a localized mass, more or less delimited, that alters the architecture of the organ.

When the neoplasm is not yet visible to the naked eye, microscopic examination reveals local distortion of the microscopic anatomy of the affected organ or tissue. The cells of the neoplasia are descendants of cells from the tissue in which it originates, which at some point express an internal alteration through uncontrolled proliferation. If the nutritional and oxygen supply are adequate, it can reach several kilos in weight, although this is uncommon.

Summary

[ disguise ]

• 1 History
• 2 Etiology
• 3 Symptoms
• 4 Difference between neoplasia and hyperplasia
• 5 Classification
• 6 Nomenclature of Mesenchymal Neoplasms
• 7 Nomenclature of other Neoplasms
• 8 Diagnosis
• 9 Forecast
• 10 Complications
• 11 Sources

History

The origin of this word dates back to Ambroise Paré ( 1517 ), who, referring to cancer, describes it like this: “Cancer is a hard, uneven tumor, rounded in shape, immobile, ash colored and surrounded by many veins full of blood, apparent and tortuous (like the feet of a fish called crab) and harder than a phlegmon or small nut, which constantly grows tormenting the sick person. This tumor has taken the name cancer due to its similarity to that animal, which when its feet adhere to something, adheres so strongly that it can barely be torn off, especially its front feet that look like pincers and pincers.

Etiology

In general, tumors seem to occur when there is a problem with cell division in the body. Generally, cell division in the body is strictly controlled: new cells are created to replace old cells or to perform new functions. Cells that are damaged or no longer needed die to make room for healthy replacement cells. If the balance of cell division and death is disturbed, a tumor can form. Problems with the body’s immune system can lead to tumors. Tobacco causes more cancer deaths than any other environmental substance. Other causes include: obesity, inactivity (sedentary lifestyle), excessive alcohol consumption, radiation, genetic problems, excessive exposure to sunlight, benzene and many other chemicals and toxins. Certain viruses may play a role in the development of tumors, such as cervical cancer and hepatocellular carcinoma. Some tumors are more common in one sex than the other, others are more common in children or the elderly, and some vary depending on diet, environment, and family history.

Symptoms

Symptoms depend on the type of tumor and its location in the body. For example, tumors in the lung can trigger cough, shortness of breath, or chest pain ; while colon tumors frequently cause weight loss, diarrhea , constipation, iron deficiency anemia , and bloody stools. Although some types of tumors may be completely asymptomatic, the following symptoms are common in most of them.

• Fever.
• Chill.
• Night sweats.
• Loss of appetite.
• Fatigue.
• General discomfort.

Difference between neoplasia and hyperplasia

Neoplasia differs from hyperplasia in the following:

• In hyperplasia, proliferation is proportional to the stimulus that causes it (when it stops acting, the hyperplasia stops growing or returns).
• In hyperplasia, the general architecture of the tissue or sector of the organ is preserved.
• In hyperplasia, a balance is reached between the number of cells produced and the number of cells lost: this balance is reached at a higher level than in normal tissue (for example, in the epidermis it is achieved with a greater number of cell layers).

Classification

Benign

• Lining epithelium: Papilloma (e.g. cutaneous squamous cell papilloma)
• Glandular epithelium: Adenoma (plus the tissue of origin, for example renal adenoma).

Evil

• Lining epithelium: Carcinoma (e.g. squamous cell carcinoma, transitional cell carcinoma).
• From glandular epithelium: Adenocarcinoma (more tissue of origin, for example, renal adenocarcinoma).

Nomenclature of Mesenchymal Neoplasms

• Benign: Tissue of more oma origin.

‘ Examples’ : osteoma, chondroma, lipoma, fibroma.

• Malignant: Tissue of origin plus sarcoma.

‘ Examples’ : osteosarcoma, chondrosarcoma, liposarcoma, fibrosarcoma. In the case of muscle neoplasms they are called as follows:

• Smooth muscle: Leiomyoma or leiomyosarcoma, depending on whether it is benign or malignant.
• Skeletal muscle: rhabdo, followed by myoma or myosarcoma according to its benign or malignant nature, respectively.

Nomenclature of other Neoplasms

Denomination by eponyms: For example:

• Ewing sarcoma
• Wilms tumor
• Grawitz tumor
• Hodgkin’s disease
• Kaposi sarcoma
• Burkitt lymphoma
• Non-epithelial or supportive neoplasms: They are named according to the tissue of origin (histogenetic nomenclature).
• Lymphoma: Neoplasia of components of the immune system.
• Melanoma: Malignant neoplasm of melanocytes, highly malignant and with extensive metastatic potential.
• Leukemia: Malignant neoplasm of circulating hematopoietic elements of the bone marrow.
• Embryonic tumors: They derive from primitive embryonic “blastic” tissue, for example: neuroblastoma , hepatoblastoma , nephroblastoma .
• Gliomas: Non-neural neoplasms of supporting tissues, and can be benign or malignant, being named according to the cell of origin (astrocytoma, oligodendroglioma).
• Germ cell tumors: Neoplasms of germ cells of the gonads and rarely of extragonadal location. For example: seminoma.
• Teratoma: Germ cell neoplasia structured by different types of tissues derived from the three embryonic layers. They can be benign or malignant, generally gonadal and more rarely extragonadal. A mature and an immature form are recognized, depending on the features presented by its components.
• Neuroendocrine tumors: Neoplasms of neuroendocrine cells, secreting active amines or polypeptide hormones (examples: adrenal pheochromocytomas , appendiceal carcinoid , medullary thyroid carcinoma , insulinoma, prolactinoma ).

There may be mixed tumors, both benign and malignant, which may show epithelial and mesenchymal components.

Diagnosis

• Macroscopic and microscopic analysis of the lesion: In order to determine its nature (benign or malignant) and evaluate morphological patterns that allow determining a grading and therefore assigning a prognosis. The tissue to be analyzed can be obtained by surgical biopsy (incisional or excisional), puncture biopsy or through endoscopic instruments, as well as tissues derived from surgical resections, including radical ones. On the other hand, a tissue obtained during an operative act can be studied by freezing it to obtain an intraoperative, rapid or frozen biopsy report (currently also called intraoperative consultation), allowing the surgeon to decide the conduct based on the information provided. by the pathologist.
• Cytology: Technique that allows analyzing isolated cells or in groups, either for diagnostic purposes or as a method of early screening (in cervical cancer).
• Electron microscopy: Sometimes used to analyze cellular structures that allow determining the histogenesis of the lesion.
• Immunocytochemistryor immunohistochemistry : Used to also determine histogenesis or make differential diagnosis between lesions of different types. They are carried out through Ag-Ac reactions with different methods, where the antibody reacts with greater or lesser specificity against a particular cellular element.

Flow cytometry: Especially to determine DNA content.

• In situ hybridization : It allows, for example, to differentiate oncogenic human papillomavirusesfrom non-oncogenic ones.
• PCR: Technique that allows studying by amplification of gene sequences, for example, oncogenes or tumor suppressor genes.
• Tumor markers: Which have greater or lesser sensitivity and specificity. It allows supporting the diagnosis of the neoplasia or can be used in follow-up.

Forecast

The prognosis varies widely between different types of tumors. If the tumor is benign, the prognosis is generally very good. However, there are some cases in which a benign tumor can cause big problems, for example, tumors in the brain. If the tumor is malignant, results vary depending on the stage of the tumor at the time of diagnosis. Some types of cancer are curable and some that are incurable can be treated well and patients can cope with the disease for years. Other tumors cause death quickly.

Complications

Complications may occur if the tumor is located in a region of the body where normal organ function is compromised. If the tumor is malignant, it can also cause complications if it spreads or metastasizes.