leptomeninges

The arachnoid and pia mater are sometimes together called the leptomeninges.

Metastasis to the leptomeninges is an uncommon but well-recognized clinical presentation in cancer patients.

Because of this continuum, the layers are often referred to as the pia arachnoid or leptomeninges.

There is monocytic and neutrophilic infiltration of the leptomeninges.

Meningeal carcinomatosis is a condition in which a solid tumor diffusely spreads to the leptomeninges.

The arachnoid and pia mater are sometimes considered as a single structure, the leptomeninx, or the plural version, leptomeninges.

The morphology of the brain in meningococcal meningitis is said to be covered by exudate on the surface of, and within the leptomeninges.

MRI with contrast may show enhancement of leptomeninges and cochlea consistent with chronic meningitis.

There the cancerous cells seed and disseminate into the leptomeninges which compose of the arachnoid and the pia.

Leptomeningeal metastasis (LM) is a rare complication of systemic cancer in which the leptomeninges are infiltrated by cancer cells.

Lung tumors, breast tumors, and malignant melanoma comprise the majority of solid tumors spreading to the leptomeninges.

Macroscopic findings include purulent exudates, opaque leptomeninges (thining of meninges), pus, and ventriculitis/ ependymitis.

Leukemia, lymphoma, breast cancer, and gastrointestinal cancer may spread to the leptomeninges (the two innermost membranes covering the brain and spinal cord).

Diffuse melanocytosis involves the supratentorial and infratentorial leptomeninges; melanocytomas occur as solid masses in the cranial and spinal compartments.

Recurrent disease is usually at the primary tumor site, though multifocal or widely disseminated disease to other intracranial sites and to the spinal leptomeninges has been documented.

Because the arachnoid is connected to the pia by cob-web like strands, it is structurally continuous with the pia, hence the name pia-arachnoid or leptomeninges.

In contrast to VRS of the basal ganglia, VRS in the cerebral cortex are surrounded by only one layer of leptomeninges.

An MRI scan is also the best diagnostic imaging choice for pituitary carcinomas; metastases may be found in the cerebral lobes, cerebellum, spinal cord, leptomeninges, and subarachnoid space.

They usually arise supratentorial and superficially from the cerebral hemispheres (upper most sections) of the brain and in contact with the leptomeninges, rarely they arise from the spinal cord.

Sites of noncontiguous relapse may include the spinal leptomeninges, intracranial sites, and cerebrospinal fluid, in isolation or in any combination, and is variably associated with primary tumor relapse.

VRS surrounding arteries in the cerebral cortex and the basal ganglia are separated from the subpial space by one or two layers of leptomeninges, respectively, as well as the pia mater.

This is distinctly different from an encephalocele, which is a herniation of brain tissue and/or leptomeninges, that develops through a defect in the skull, where there is a continuity with the cranial cavity.

In medicine, leptomeninges (literally thin meninges) is a term used to refer to the pia mater and arachnoid mater, two of the membranes that surround the brain and the spinal cord.

MELANOCYTIC LESIONS are diffuse or circumscribed, benign, or malignant tumors arising from melanocytes of the leptomeninges.

Meningoencephalitis characterized by perivascular cuffing with proliferating adventitial cells, histiocytes, and a few plasma cells was seen in the gray and white matter of the cerebrum and in the leptomeninges of PPV-infected stillborn pigs.