Clinical Neurology and Neurosurgery 111 (2009) 87–93 Contents lists available at ScienceDirect Clinical Neurology and Neurosurgery journal homepage: www.elsevier.com/locate/clineuro Case report Systemic cancer metastasis in a meningioma: Report of two cases and review of the literature Michele Lanotte a,* , Franco Benech a , Pier Paolo Panciani a , Paola Cassoni b , Alessandro Ducati a a Institute of Neurosurgery, Department of Neuroscience, University of Torino, Via Cherasco 15, I-10126 Torino, Italy b Department of Biomedical Sciences and Human Oncology, University of Torino, Torino, Italy article info Article history: Received 9 April 2008 Received in revised form 27 June 2008 Accepted 1 July 2008 Keywords: Tumour-to-tumour metastasis Meningioma Breast carcinoma Clear cell renal carcinoma abstract “Tumour-to-tumour” phenomenon is a rare event; meningioma has been reported as the most common primary intracranial tumour to harbour metastases, the majority of which arise from breast and lung carcinomas. Several hypotheses have been previously proposed to explain this occurrence, but the exact mechanisms responsible for the development of metastases in meningiomas are not known. Magnetic resonance imaging (MRI) and spectroscopy could be useful to hypothesize this uncommon event, but its preoperative diagnosis remains highly difficult. Two patients are reported, with breast and renal carcinoma metastases in an intracranial meningioma. Pathogenetic mechanisms and neuroimaging features are discussed. A brief review of the literature is presented. © 2008 Elsevier B.V. All rights reserved. 1. Introduction Metastases of systemic cancer to intracranial tumours, albeit rare, have been reported in the literature since 1930, mostly into meningiomas and, less frequently, in acoustic neurinomas, gliomas and pituitary adenomas [1]. Breast and lung are the most common sources of tumour-to- tumour metastasis, while kidney, thyroid, prostate and colon seem to be very rare [2,3]. Many hypotheses have been postulated to explain this phe- nomenon: haemodynamic, metabolic, hormonal, and molecular. However, the exact mechanism still remains unknown. We herein report two patients with breast and renal carcinoma metastases into an intracranial meningioma. 2. Clinical report 2.1. Case 1 A 64-year-old woman was admitted to our institution with headache, progressive right hemiparesis and dysphasia. The patient had undergone a right mastectomy and radiotherapy for breast carcinoma 10 years ago. A CT of the brain revealed a hyper- dense left fronto-temporal lesion, surrounded by peritumoural * Corresponding author. Tel.: +39 011 633 4243; fax: +39 011 633 4243. E-mail address: michele.lanotte@unito.it (M. Lanotte). edema, which presented marked enhancement. Cranial magnetic resonance imaging (MRI) showed few hypointense areas sur- rounded by a diffuse hyperintense lesion; contrast-enhanced MRI showed homogeneous enhancement of the whole mass and a few hypointense areas with hyperintense rims in the enhancing mass (Fig. 1). Cerebral angiography showed a late tumoural blush due to some branches originating from the middle meningeal artery. The patient underwent a left fronto-temporal craniotomy. A well-circumscribed greyish-white nodular mass was completely removed. The post-surgical course was uneventful. Histopatholog- ical findings yielded a diagnosis of metastasis. Postoperative local radiation therapy and chemotherapy were administered. After- wards, vertebral metastases occurred and the patient died 20 months after diagnosis for the dissemination of the mammary dis- ease. 2.2. Case 2 A 61-year-old male was admitted to the hospital because of a mass in his right kidney. He underwent a right-sided nephrec- tomy; pathological examination revealed an invasive renal cell carcinoma (Fuhraman G2-G3; pT2 pN0). In the screening a small (<1 cm) asymptomatic pulmonary nodule was detected by CT imag- ing. Serial CT did not show a progression of the lesion. Three years later he presented with vertigo, diplopia, headache, nausea and vomiting. On neurological examination abducting nys- tagmus, dysphagia, dysphonia and left tongue deviation were observed. MRI demonstrated a foramen magnum extra-axial mass 0303-8467/$ – see front matter © 2008 Elsevier B.V. All rights reserved. doi:10.1016/j.clineuro.2008.07.011