Atypia (from

Greek Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...

, ''a'' + ''typos'', without type; a condition of being irregular or nonstandard) is a

histopathologic Histopathology (compound of three Greek language, Greek words: 'tissue', 'suffering', and ''-logy, -logia'' 'study of') is the light microscope, microscopic examination of Tissue (biology), tissue in order to study the manifestations of dis ...

term for a structural abnormality in a

cell Cell most often refers to: * Cell (biology), the functional basic unit of life * Cellphone, a phone connected to a cellular network * Clandestine cell, a penetration-resistant form of a secret or outlawed organization * Electrochemical cell, a de ...

, i.e. it is used to describe atypical cells. Atypia can be caused by infection or irritation. If, for example it were diagnosed in a

Pap smear The Papanicolaou test (abbreviated as Pap test, also known as Pap smear (AE), cervical smear (BE), cervical screening (BE), or smear test (BE)) is a method of cervical screening used to detect potentially precancerous and cancerous processes in ...

in the

uterus The uterus (from Latin ''uterus'', : uteri or uteruses) or womb () is the hollow organ, organ in the reproductive system of most female mammals, including humans, that accommodates the embryonic development, embryonic and prenatal development, f ...

it is more likely to be precancerous. The related concept of

dysplasia Dysplasia is any of various types of abnormal growth or development of cells (microscopic scale) or organs (macroscopic scale), and the abnormal histology or anatomical structure(s) resulting from such growth. Dysplasias on a mainly microscopic ...

refers to an abnormality of development, and includes abnormalities on larger,

scales.

Example features

Features that constitute atypia have different definitions for different diseases, but often include the following

nucleus Nucleus (: nuclei) is a Latin word for the seed inside a fruit. It most often refers to: *Atomic nucleus, the very dense central region of an atom *Cell nucleus, a central organelle of a eukaryotic cell, containing most of the cell's DNA Nucleu ...

abnormalities: *Enlargement * Pleomorphism *Nuclear polychromasia, which means variability in nuclear

chromatin Chromatin is a complex of DNA and protein found in eukaryote, eukaryotic cells. The primary function is to package long DNA molecules into more compact, denser structures. This prevents the strands from becoming tangled and also plays important r ...

content. Polychromasia otherwise refers to a disease of immature red blood cells. *Numerous mitotic figures

Examples for Barrett's esophagus

Barrett's esophagus Barrett's esophagus is a condition in which there is an abnormal ( metaplastic) change in the mucosal cells that line the lower part of the esophagus. The cells change from stratified squamous epithelium to simple columnar epithelium, intersper ...

, features that are classified as atypia but not as

are mainly: *''Nuclear stratification'', wherein cell nuclei, which are normally located nearly at the same level between adjacent cells, are instead located at different levels. *Crowding *Hyperchromatism *Prominent

nucleoli The nucleolus (; : nucleoli ) is the largest structure in the nucleus of eukaryotic cells. It is best known as the site of ribosome biogenesis. The nucleolus also participates in the formation of signal recognition particles and plays a ro ...

Prognosis

It may or may not be a

precancerous A precancerous condition is a condition, tumor or lesion involving abnormal cells which are associated with an increased risk of developing into cancer. Clinically, precancerous conditions encompass a variety of abnormal tissues with an increase ...

indication associated with later

malignancy Malignancy () is the tendency of a medical condition to become progressively worse; the term is most familiar as a characterization of cancer. A ''malignant'' tumor contrasts with a non-cancerous ''benign'' tumor in that a malignancy is not ...

, but the level of appropriate concern is highly dependent on the context with which it is diagnosed. For example, already differentiated, specialised cells such as epithelia displaying "cellular atypia" are far less likely to become problematic (cancerous/malignant) than are

myeloid progenitor cells Hematopoietic stem cells (HSCs) are the stem cells that give rise to other blood cells. This process is called haematopoiesis. In vertebrates, the first definitive HSCs arise from the ventral endothelial wall of the embryonic aorta within the ...

of the immune system. The 'further back' in an already specialised, differentiated cell's lineage, the more problematic cellular atypia is likely to be. This is due to the conferring of such atypia to progeny-cells further down the lineage of that cell type.

References

{{reflist Pathology Medical terminology Dermatologic terminology Oncology Gynaecology

Example features

Examples for Barrett's esophagus

Prognosis

See also

References