Metastatic renal cell carcinoma in a meningioma: A case report

Tumor-to-tumor metastasis is rare. We report a case of metastatic renal cel l carcinoma in meningioma. A 67-year-old woman presented a two-week history of motor dysphagia and decreased short-term memory. She had undergone a le ft radical nephrectomy for a renal cell carcinoma 7 years ago and had not r eceived any adjuvant therapy. MRI disclosed a 3.0 x 3.0 x 3.0-cm sized roun d tentorial-based extraaxial mass with peritumoral edema in the left poster ior temporal lobe. During operation, the tumor was found to be an encapsula ted mass firmly attached to the tentorium. Histologically, the tumor was a meningotheliomatous meningioma extensively infiltrated by metastatic renal cell carcinoma, accompanying widespread coagulative necrosis. Immunohistoch emical staining for cytokeratin revealed strong positivity only in the rena l cell carcinoma component. The patient's postoperative course was uneventf ul. Post-operative radiation therapy was applied to the whole brain. Three months after operation, the patient developed right hemiparesis and dysphag ia. Brain MRI at that time did not reveal recurrence or any other causative lesions, although the whole body scan disclosed uptake at the second lumba r vertebra and rib. The patient refused further treatment.