Even if, by general rule, neoplasms of the nervous system (brain tumors) cannot metastasize into the body because of the blood–brain barrier, anaplastic meningioma can. Although they are inside the cerebral cavity, they are located on the bloodside of the BBB, because meningiomata tend to be connected to blood vessels. Thus, cancerized cells can escape into the bloodstream, which is why meningiomata, when they metastasize, often turn up around the lungs.Anaplastic meningioma and hemangiopericytoma are difficult to distinguish, even by pathological means, as they look similar, especially, if the first occurrence is a meningeal tumor, and both tumors occur in the same types of tissue.Although usually benign a "petro-clival" menigioma is typically fatal without treatment due to its location. Until the 1970s no treatment was available for this type of meningioma; however, since that time a range of surgical and radiological treatments have evolved. Nevertheless, the treatment of this type of meningioma remains a challenge with relatively frequent poor outcomes. Prevention
The risk of meningioma can be reduced by maintaining a normal body weight, and by avoiding unnecessary dental x-rays. Treatment
Observation
Observation with close imaging follow-up may be used in select cases if a meningioma is small and asymptomatic. In a retrospective study on 43 patients, 63% of patients were found to have no growth on follow-up, and the 37% found to have growth at an average of 4 mm / year. In this study, younger patients were found to have tumors that were more likely to have grown on repeat imaging; thus are poorer candidates for observation.
Baritosis is a benign type of pneumoconiosis, which is caused by long-term exposure to barium dust. Barium has a high radio-opacity and the disease may develop after few months of exposure. Extremely dense, discrete small opacities of 2–4 mm diameter, sometimes of a star-like configuration, are seen on the radiograph. Their distribution is uniform. When they are very numerous, superimposition may give the impression of confluency, but this does not seem to occur in reality. The hilar lymph nodes can be very opaque but not enlarged. After cessation of exposure, there is a gradual clearing of the opacities. Symptoms and signs
Cough
Wheezing
Nasal irritationIn some cases, it is asymptomatic. Diagnosis
The barium particles can be seen as opaque shadows on the chest X-rays of people with baritosis. However, being a benign condition, it neither interferes with lung function nor causes symptoms other than a mild cough.After exposure to barium dust ceases, the X-ray abnormalities gradually resolve. Treatment
Reference

http://www.wrongdiagnosis.com/b/baritosis/intro.htm


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