Incidental Bone Lesions in a 78 Year Old Male with History of Grade I Meningioma

The clinical phenomenon of metastatic meningioma is not well described in the literature owing to the relative rarity of its incidence. We report the case of a 78 year old male with a past medical history notable for successfully resected. WHO grade I meningioma in June of 2006 who, upon presentation for left thigh pain from a traumatic fall eight years later, was found to have incidental imaging findings of multiple bony lesions in the left iliac crest and spine. Subsequent investigations revealed the diagnosis of WHO grade I meningioma metastatic to the bone. Although its unequivocal rarity would reasonably relegate metastatic meningioma to a diagnosis of exclusion, it is hoped that this case report will prevail upon the reader the importance of keeping this diagnostic possibility on the differential in the appropriate clinical context. Siddarth Joshi, Cristian Dobre, Murat Anamur and Richard Zuniga* Tuality Healthcare, USA Hematology-Oncology, Lowell General Cancer Center, USA Richard Zuniga, et al., Clinics in Oncology Central Nervous System Tumours Remedy Publications LLC., | http://clinicsinoncology.com/ 2016 | Volume 1 | Article 1162 2 diagnosis of grade I meningioma. Given the fact that the patient was minimally symptomatic from the meningioma the decision was made to monitor only and no medical intervention was initiated. Discussion Among all of the primary CNS tumors, meningiomas are the most common, numbering roughly one in every three primary tumors found in the brain and spinal cord [1]. Meningiomas have a gender predilection for females, the female to male ratio being about 2-3:1 [2]. The incidence of meningioma also has a positive correlation with the advancement of age, with the median age at diagnosis being 65 years. Multiple investigations have been undertaken to establish possible etiologies for the development of meningioma. The most prominent etiologic association is history of CNS exposure to ionizing radiation, including radiation therapy used to treat other primary malignancies [3,4]. Our patient has no such history. Less commonly, there are certain genetic mutations implicated in the development of meningioma. The most well established is mutation of the NF2 tumor suppressor gene that results in neurofibromatosis type 2 (NF2) [5]. As a consequence of this mutation, patients with this syndrome are typically found to develop distinct simultaneous malignant entities, predominantly vestibular schwannomas and gliomas [6]. As many as 50% of these patients have at least one meningioma but are oftentimes afflicted with multiple tumors [5]. There are other less prominent risk factors which include hormonal factors, the concomitant presence of breast cancer, obesity and head trauma [7,8,9]. Meningiomas are classified by the WHO based on morphology and histopathological characteristics; the latest iteration was rendered in 2007 [10]. Meningiomas are delineated into 3 broad groups: Grade I (benign), Grade II (atypical), and Grade III (malignant). The vast majority (90%) of meningiomas are Grade I tumors [11]. There are distinct clinical characteristics and behaviors that distinguish Grade II and III meningiomas from Grade I meningiomas; these are: increased proclivity for invasion into local brain parenchyma, an increased likelihood of recurrence following initial treatment, and a shorter overall survival [12]. All three characteristics are seen to the greatest degree in grade III meningiomas and to a lesser extent in grade II meningiomas [13,14]. Grade I meningiomas, on the other hand, infrequently recur, do not exhibit invasion into surrounding brain structures, and have a considerably longer overall survival and better prognosis [15]. The risk of recurrence after initial treatment rises successively with increasing tumor grade and atypical histopathological features which include high cellularity, tumor necrosis, high mitotic rate and vascular invasion [16]. The present case defies these general conventions insofar as the patient had an indolent recurrence of his original grade I tumor after complete surgical resection. Another telling difference that distinguishes Grade I meningioma from Grade II/III meningioma is the likelihood of extracranial Figure 1: Axial CT image of the head demonstrate a mildly hyperdense left posterior parafalcine mass compatible with a meningioma.