#malformation

• Abrachia — An extremely rare congenital malformation characterized by the complete absence or rudimentary development of the arms (upper limbs) in a fetus or developing organism; a severe anatomical anomaly within the category of limb agenesis, similar to or closely related to amelia and congenital abrachia.
• Abrachiocephalus — A teratological monster, fetus, or organism with severe congenital malformations, characterized by the simultaneous absence of both arms and the head, or by the abnormal and rudimentary fusion of cephalic structures in the complete absence of upper limbs; (adjectival) presenting the anatomical features of this embryonic developmental anomaly.
• Abrachiocephaly — A complex and extremely severe congenital malformation characterized by the simultaneous absence of both the head (acephalia) and both upper limbs (abrachia) in a fetus or developing organism; an early embryonic developmental anomaly, incompatible with life, studied within classical and experimental teratology.
• Acardia — A congenital absence of the heart or a complete cessation in the ontogenetic development of the cardiac structure in a fetus. This severe structural anomaly is incompatible with independent extrauterine life and is documented almost exclusively within monochorionic multiple pregnancies with asymmetric development (TRAP sequence), where the affected fetus's blood circulation is maintained solely by its twin's heart through placental vascular anastomoses.
• Acrodolichomelia — A rare congenital structural malformation or anatomical feature characterized by disproportionate and excessive length of the distal segments of the limbs (hands and feet relative to arms and thighs, or unusually long digits).
• Acrodolichomelia — A spelling variant or medical transcription error for acrodolichomelia, describing a rare congenital structural malformation characterized by disproportionate and excessive length of the distal segments of the limbs.
• Acromacria — A rare congenital structural malformation or skeletal development anomaly characterized by the disproportionate, excessive length and thinning of the distal segments of the limbs, especially the digits.
• Adactyly — A rare congenital malformation characterized by the total or partial absence of fingers or toes. This structural anomaly of embryonic development can occur in isolation or as part of a complex malformativ syndrome, determined by genetic mutational factors or external teratogenic insults suffered by the embryo during the first weeks of pregnancy.
• Agastria — An extremely rare congenital malformation consisting of the total absence of the stomach from birth; by extension, the anatomical and clinical state resulting from a total gastrectomy (complete surgical removal of the organ). Structurally, this condition disrupts the normal digestive pathway, requiring a surgical restructuring of the tract by directly connecting the esophagus to the jejunum (esophagojejunostomy) and a strict nutritional regimen.
• Amyelencephalus — A medical term from the field of teratology denoting a fetus or congenitally malformed organism structurally characterized by the total absence or severely impaired development of the spinal cord (amyelia) and the myelencephalon (embryonic medulla oblongata). This severe neurological anomaly is incompatible with life and is investigated within major neural tube defects.
• Amyelia — An extremely rare and severe congenital malformation within the neural tube defects spectrum, characterized by the total absence or complete developmental arrest of the spinal cord. This severe structural anomaly occurs during the first weeks of embryogenesis due to the failure of the posterior neuropore to close, being incompatible with extrauterine life and often associated with other major cranial malformations.
• Anencephalic — The feminine form of 'anencefal'; describing an organic structure, a pregnancy, or a female biological entity characterized by the total or partial congenital absence of the brain and cranial vault. The term is frequently utilized in medical imaging and obstetrics to qualify severe malformations detected during fetal morphology scans.
• Anencephaly — An extremely severe, lethal congenital malformation characterized by the total or partial absence of the cerebral hemispheres, cerebellum, and cranial vault, caused by the failure of the anterior neuropore to close during embryogenesis (days 23-26). This major structural condition is incompatible with long-term survival, with most cases resulting in stillbirth or death shortly after birth.
• Aneresis — A rare congenital malformation or structural anomaly characterized by the partial or total absence of the anus, often associated with anal imperforation or the presence of abnormal rectal fistulas. Clinically and functionally, this severe bio-structural condition blocks the normal evacuation of fecal matter in the newborn, requiring emergency reconstructive surgical intervention immediately after birth.
• Angiodisplasia — A congenital or acquired vascular malformation, characterized by the abnormal dilation and fragility of capillary and venular vessels within the mucosa of the digestive tract, particularly in the ascending colon and cecum. This clinical structural anomaly represents a major cause of occult or overt gastrointestinal bleeding in elderly patients, being diagnosed endoscopically as stellate, reddish lesions prone to recurrent hemorrhages.
• Angioma — A benign tumorous formation or well-defined congenital malformation, developed through the abnormal proliferation and crowding of blood vessels (hemangioma) or lymphatic vessels (lymphangioma). Clinically manifested as red-purple patches or nodules on the skin, mucous membranes, or internal organs (frequently on the liver or brain), this structural element generally has a slow and non-invasive evolution but can associate bleeding risks in case of local mechanical trauma.
• Anorectal — Relating to both the anus and the rectum, belonging to or located at the level of the terminal segment of the digestive tract. In a clinical and structural context, the term describes the muco-cutaneous junction zone, the sphincter apparatus, as well as site-specific pathologies (such as abscesses, fistulas, or malformations), defining an anatomical territory of crucial importance for fecal continence.
• Aoria — A rare medical term used to describe the congenital absence, severe atrophy, or lack of structural development of the aorta, the primary artery of the human body. This extremely severe pathological phenomenon directly affects the systemic circulation and requires complex surgical intervention immediately after birth to ensure organism survival.
• Apodia — An extremely rare congenital malformation characterized by the complete, unilateral or bilateral, absence of feet or lower limbs at birth; a severe structural anomaly of embryonic development. In teratological practice, this condition is studied in close connection with dysmelia and phocomelia, representing the early developmental arrest of lower limb buds.
• Aproctia — An extremely rare congenital malformation characterized by the complete absence, imperforate state, or congenital structural occlusion of the anal orifice (anus). This anatomical phenomenon requires emergency pediatric surgical intervention immediately after birth to create an artificial elimination pathway and restore normal physiological functions.