Pronunciation: [ˈalantˌə͡ʊɪk sˈɪst] (IPA) 
The term "allantoic cyst" refers to a cyst that develops from the allantois, a structure in embryonic development. The correct spelling of this word can be explained using the International Phonetic Alphabet (IPA). In IPA, "al" is pronounced as /æl/, "lan" as /læn/, "to" as /toʊ/, "ic" as /ɪk/, and "cyst" as /sɪst/. Combining these sounds, the correct spelling can be transcribed as /æˌlæntoʊɪk ˈsɪst/.
An allantoic cyst is an abnormal sac-like structure that forms in the allantoic cavity of embryos in certain animal species, particularly birds and reptiles. The allantoic cavity is a fluid-filled sac that develops during embryonic development and functions to store metabolic waste and allow gas exchange between the embryo and its surrounding environment.
The allantoic cyst arises when the allantois, a temporary structure formed during early development, fails to properly regress or absorb. This leads to the formation of a cyst-like growth within the allantoic cavity. These cysts can vary in size and may contain fluid or other types of material.
Allantoic cysts are often incidental findings during postmortem examinations or imaging studies. They are typically observed within the abdominal cavity, attached to the allantoic sac, or near the umbilicus.
While most allantoic cysts are benign and usually do not cause any clinical signs or symptoms, large cysts may put pressure on adjacent structures, leading to discomfort or complications. In such cases, surgical removal or drainage may be necessary.
Allantoic cysts are distinct from umbilical cysts, which develop within the umbilical region and are unrelated to the allantoic cavity. These cysts are often temporary and typically resolve spontaneously without intervention. However, if they cause symptoms or complications, appropriate medical evaluation and management may be required.
A circumscribed dilatation of the urachus.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.
The word "allantoic cyst" originates from the combination of two primary terms: "allantoic" and "cyst".
1. Allantoic: The term "allantoic" is derived from the Latin word "allantois", referring to a specialized extraembryonic membrane found in developing embryos of reptiles, birds, and mammals. The allantois plays a crucial role in the exchange of gases and waste disposal. It developed its meaning in English in the late 19th century.
2. Cyst: The word "cyst" comes from the Greek term "kystis", meaning "bladder" or "pouch". It has been used to describe anatomical structures or abnormalities characterized by an encapsulated cavity or sac filled with fluid or semi-solid material. The term has been part of medical vocabulary since ancient times.
