INTRACRANIAL MENINGIOMA MASQUERADING AS A PRIMARY PLEUROPULMONARY TUMOR

Extracranial metastasis was found in an intracranial meningioma with l ow proliferative potential before the detection of the primary tumor, Pleuropulmonary tumors were incidentally detected on chest X-ray in an asymptomatic 25 year old female. Excised tumors of the right pleura a nd lung showed histological features similar to meningotheliomatous me ningioma, which led to the discovery and excision of the intracranial tumor, Both tumors showed the same histologic pattern: meningothelioma tous meningioma with low mitotic activity, The proliferative component , determined by the monoclonal antibody Ki-67, was further evaluated i n the primary tumor and the metastases of the present case, as well as in 12 other intracranial meningiomas, Ki-67 positive ratios at the pr imary and metastatic sites of the present case were 1.2 and 1.1%, resp ectively, which is as low as other benign meningiomas, and this sugges ts that factors other than the proliferative potential is responsible for extracranial metastasis of meningioma.