Nuclear atypia refers to abnormal appearance of cell nuclei. It is a term used in cytopathology and histopathology. Atypical nuclei are often pleomorphic.
Nuclear atypia can be seen in reactive changes, pre-neoplastic changes and malignancy. Severe nuclear atypia is, in most cases, considered an indicator of malignancy.
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The atomic number or nuclear charge number of a chemical element is the charge number of an atomic nucleus. For ordinary nuclei, this is equal to the proton number (np) or the number of protons found in the nucleus for every atom of that element. The atomic number can be used to uniquely identify ordinary chemical elements. In an ordinary uncharged atom, the atomic number is also equal to the number of electrons.
Nuclear fusion is a reaction in which two or more atomic nuclei are combined to form one or more different atomic nuclei and subatomic particles. The difference in mass between the reactants and products is manifested as either the release or absorption of energy. This difference in mass arises due to the difference in nuclear binding energy between the atomic nuclei before and after the reaction. Nuclear fusion is the process that powers active or main sequence stars and other high-magnitude stars, where large amounts of energy are released.
The term p-process is used in two ways in the scientific literature concerning the astrophysical origin of the elements (nucleosynthesis). Originally it referred to a proton capture process which is the source of certain, naturally occurring, neutron-deficient isotopes of the elements from selenium to mercury. These nuclides are called p-nuclei and their origin is still not completely understood. Although it was shown that the originally suggested process cannot produce the p-nuclei, later on the term p-process was sometimes used to generally refer to any nucleosynthesis process supposed to be responsible for the p-nuclei.
In nuclear physics and nuclear chemistry, a nuclear reaction is a process in which two nuclei, or a nucleus and an external subatomic particle, collide to produce one or more new nuclides. Thus, a nuclear reaction must cause a transformation of at least one nuclide to another. If a nucleus interacts with another nucleus or particle and they then separate without changing the nature of any nuclide, the process is simply referred to as a type of nuclear scattering, rather than a nuclear reaction.
Nuclear binding energy in experimental physics is the minimum energy that is required to disassemble the nucleus of an atom into its constituent protons and neutrons, known collectively as nucleons. The binding energy for stable nuclei is always a positive number, as the nucleus must gain energy for the nucleons to move apart from each other. Nucleons are attracted to each other by the strong nuclear force. In theoretical nuclear physics, the nuclear binding energy is considered a negative number. In this context it represents the energy of the nucleus relative to the energy of the constituent nucleons when they are infinitely far apart. Both the experimental and theoretical views are equivalent, with slightly different emphasis on what the binding energy means.
Anaplasia is a condition of cells with poor cellular differentiation, losing the morphological characteristics of mature cells and their orientation with respect to each other and to endothelial cells. The term also refers to a group of morphological changes in a cell that point to a possible malignant transformation.
A koilocyte is a squamous epithelial cell that has undergone a number of structural changes, which occur as a result of infection of the cell by human papillomavirus (HPV). Identification of these cells by pathologists can be useful in diagnosing various HPV-associated lesions.
Atypia is a histopathologic term for a structural abnormality in a cell, i.e. it is used to describe atypical cells.
Granular cell tumor is a tumor that can develop on any skin or mucosal surface, but occurs on the tongue 40% of the time.
Endometrial hyperplasia is a condition of excessive proliferation of the cells of the endometrium, or inner lining of the uterus.
The atomic nucleus is the small, dense region consisting of protons and neutrons at the center of an atom, discovered in 1911 by Ernest Rutherford based on the 1909 Geiger–Marsden gold foil experiment. After the discovery of the neutron in 1932, models for a nucleus composed of protons and neutrons were quickly developed by Dmitri Ivanenko and Werner Heisenberg. An atom is composed of a positively charged nucleus, with a cloud of negatively charged electrons surrounding it, bound together by electrostatic force. Almost all of the mass of an atom is located in the nucleus, with a very small contribution from the electron cloud. Protons and neutrons are bound together to form a nucleus by the nuclear force.
A renal oncocytoma is a tumour of the kidney made up of oncocytes, epithelial cells with an excess amount of mitochondria.
Papillary urothelial neoplasm of low malignant potential (PUNLMP) is an exophytic, (microscopically) nipple-shaped pre-malignant growth of the lining of the upper genitourinary tract, which includes the renal pelvis, ureters, urinary bladder and part of the urethra.
A subependymoma is a type of brain tumor; specifically, it is a rare form of ependymal tumor. They are usually in middle aged people. Earlier, they were called subependymal astrocytomas.
The concept of grading of the tumors of the central nervous system, agreeing for such the regulation of the "progressiveness" of these neoplasias, dates back to 1926 and was introduced by P. Bailey and H. Cushing, in the elaboration of what turned out the first systematic classification of gliomas.
In the following, the grading systems present in the current literature are introduced. Then, through a table, the more relevant are compared.
A radial scar, formally radial scar of the breast, is a benign breast lesion that can radiologically mimic malignancy, i.e. cancer.
A solid pseudopapillary tumour is a low-grade malignant neoplasm of the pancreas of papillary architecture that typically afflicts young women.
Arias-Stella reaction, also Arias-Stella phenomenon, is a benign change in the endometrium associated with the presence of chorionic tissue.
Pleomorphism is a term used in histology and cytopathology to describe variability in the size, shape and staining of cells and/or their nuclei. Several key determinants of cell and nuclear size, like ploidy and the regulation of cellular metabolism, are commonly disrupted in tumors. Therefore, cellular and nuclear pleomorphism is one of the earliest hallmarks of cancer progression and a feature characteristic of malignant neoplasms and dysplasia. Certain benign cell types may also exhibit pleomorphism, e.g. neuroendocrine cells, Arias-Stella reaction.
Smooth muscle tumor of uncertain malignant potential, abbreviated STUMP, is an uncommon tumor of the uterine smooth muscle that may behave like a benign tumor or a cancerous tumor.