heterotopic

Heterotopic is an adjective used in medicine to describe tissue or structures that are normal in architecture but located in an abnormal place. The term derives from Greek heteros ('other') and topos ('place'). In clinical practice, heterotopia refers to tissue that has developed normally but is found in an atypical location, often as a congenital anomaly or secondary to injury or disease.

It is commonly applied across organ systems and conditions, including the gastrointestinal tract, nervous system, reproductive system, and musculoskeletal system. The term is sometimes used interchangeably with ectopic, though many sources reserve heterotopic for tissue that is histologically normal when displaced.

Examples include heterotopic pancreas, where pancreatic tissue is found in the stomach or duodenum; heterotopic ossification, formation of bone within soft tissues after trauma or neurologic injury; and heterotopic brain tissue, such as nodular heterotopia in the brain that can be involved in developmental epilepsy. A well-known clinical use is heterotopic pregnancy, the simultaneous occurrence of intrauterine and ectopic gestations.

Diagnosis typically relies on imaging and, when feasible, histology. Management depends on location and symptoms: asymptomatic heterotopia may require no treatment, whereas symptomatic or life-threatening cases (such as heterotopic pregnancy or extensive ossification) may require medical or surgical intervention. The term serves as a general descriptor for displacement of tissue that remains of normal type.