plexiform

Plexiform is an adjective derived from the Latin plexus, meaning a network or braid. In science and medicine, it describes a growth pattern or organization that forms a branching, interwoven network of fibers, cells, or vessels spread over a region rather than appearing as a solid lump.

In pathology, plexiform indicates a diffuse, network-like spread along tissues or nerves. A well-known example is plexiform neurofibroma, a nerve sheath tumor that grows as a network of interlacing nodules along one or more nerves. Plexiform neurofibromas are associated with neurofibromatosis type 1 and can involve large portions of a limb or other body regions; they may carry a risk of malignant transformation in rare cases. The term is also used for other diffuse, network-like tumors and conditions, including plexiform glioma, a diffuse, low-grade brain tumor seen in some individuals with neurofibromatosis type 1, and, in pulmonology, plexiform lesions composed of proliferating cells within small pulmonary arteries.

In anatomy and histology, plexiform describes layered, interconnected neural or vascular networks. The retina contains the outer plexiform layer and the inner plexiform layer, where synaptic connections form between photoreceptors, bipolar, amacrine, and horizontal cells. These layers reflect the concept of a network of interwoven processes rather than discrete, isolated cells.

The term emphasizes patterning rather than a single mass, conveying a networked, sprouting arrangement in tissues and organs.

See also: plexus, plexiform layer, plexiform neurofibroma, plexiform glioma, plexiform lesion.