Dystopia

DYSTOPIA, dystopia (from Greek dys - a prefix indicating qualitative impairment and topos - place), displacement, ^: - a term used to denote the incorrect position (i.e., as if displaced from its usual place) of individual cells, tissue segments, and entire organs. Dystopia is mostly a congenital phenomenon, i.e., a developmental defect of tissue or organ; however, cases of dystopia occurring postnatally as a subsequent development of various parts of the body may be observed. Examples of cellular dystopia may include cases where individual Purkinje cells of the cerebellum are found not in their usual cortical layer but in its granular layer, or the presence of individual nerve cells among the nerve fibers of the lateral columns or roots of the spinal cord. Tissue dystopia is illustrated by findings of cartilaginous tissue (from the II branchial arch) among the tissue of the tonsil, mucous membrane tissue of the stomach in the esophagus, etc. Organ dystopia most often concerns the kidneys and testes; one kidney may be found not in its usual place but at the entrance to the pelvis or within the pelvis. The testicle sometimes descends not into the scrotum but under the skin of the perineum (d. peri-nealis testiculi) or both testicles are found in one half of the scrotum (d. trans-versa testiculorum; see also Heterotopia).