meningeal carcinomatosis
Meaning of meningeal carcinomatosis: One condition carrying at least five names, recognized by trouble that refuses to point to a single spot in the nervous system.
Definition of meningeal carcinomatosis
Meningeal carcinomatosis is cancer that has spread in a thin sheet across the membranes wrapping the brain and spinal cord instead of forming a single lump. The deposits coat those surfaces and shed cells into the fluid around them. Because that fluid bathes the whole nervous system, the symptoms come from scattered sites rather than from one identifiable place.
How does it differ from a deposit inside the brain?
| Feature | Deposit in brain tissue | Meningeal carcinomatosis |
|---|---|---|
| Shape | A discrete lump within the brain | A film coating surfaces and nerve roots |
| Symptoms | Match the region affected | Scattered, at several levels at once |
| On a scan | A rounded mass with swelling around it | Fine lines of enhancement along surfaces |
| Spinal fluid | Usually unremarkable | Cancer cells, high protein, low sugar |
Why does it carry so many names?
Each name describes the same finding from a different angle, and all remain in use. Carcinomatosis means carcinoma scattered widely rather than gathered in one place. Carcinomatous meningitis borrows the word for inflamed membranes, because the spinal fluid looks strikingly like that of an infection even though no organism is present. Leptomeningeal metastasis is the most neutral of them, since it specifies the inner membranes without claiming the cells came from a carcinoma at all. When they come from a blood cancer, the parallel term is meningeal leukemia. Lymphoma and melanoma produce the identical picture under names of their own.
How is it identified?
Two examinations carry the diagnosis. Spinal fluid is drawn through a needle in the lower back and examined for cancer cells, and because a single sample misses a substantial share of cases, sampling is often repeated. Magnetic resonance imaging of the brain and the entire spine, taken with contrast, shows the coating along surfaces and nerve roots, and may reveal blockage of fluid flow. Both are needed, since either can be normal while the other is not. It occurs late in the course of a solid tumor, most often from breast cancer or lung cancer, and treatment is directed at controlling symptoms and at delivering drugs into the fluid itself, since most given by mouth or vein reach it poorly.
Also known as
Used in a sentence
Meningeal carcinomatosis was suspected after cranial nerve findings appeared at several levels.
Good to know
Spinal fluid in this condition can resemble bacterial meningitis, with high protein and low sugar, although no organism is present, and a single negative fluid sample does not exclude the diagnosis.
Word origin
Where “meningeal carcinomatosis” comes from
Meninx is the Greek for membrane, and the ending -osis marks a condition, so the word describes a state of carcinoma scattered through the membranes.