Intraosseous tumor was found in a 63 year old male patient with lung cancer 
during metastatic work-up study. Plain skull X-ray film showed a large 
osteolytic lesion in the left temporo-parietal bone. Bone and Ga scintigrams 
revealed an increased activity in this lesion. CT scan demonstrated an isodense 
lentiform configuration, which was homogeneously enhanced with contrast medium. 
It was iso-intense in T1, and high-intense in T2 and proton weighted MR images. 
The tumor was removed en bloc with surrounding normal bone. The attached dura 
was markedly thickened, but there was no tumor infiltration. Histological 
diagnosis was transitional meningioma with psammoma body. Postoperatively he was 
transferred back to Okinawa Hospital and right lower lobectomy was performed for 
the lung tumor. Histological diagnosis was well-differentiated adenocarcinoma. 
We examined immunohistochemically p53 protein expression, but p53 immunoactivity 
was observed in neither tumor. Multiple neoplasms associated with brain tumor 
are relatively rare, but the incidence will increase in the future as the 
diagnostic work-up develops. Pathological diagnosis will give us the decisive 
opportunity for proper treatment. It is to be stressed that, in multiple 
neoplasms, care should be taken to avoid misdiagnosis of metastasis.