Search

We report a case of an osteochondroma in a 47-year-old woman presenting with a 2-month history of thoracic back pain that radiated down her left arm. Based on imaging features, the osteochondroma was initially thought to represent a calcified meningioma. The unusual features of the case include the location of the tumor, patient age, the erosion of the vertebra, and the confusing neuroradiological features. We review reported cases in which a solitary costal osteochondroma impinges on the neural foramina or central spinal canal and we discuss reasons for the misdiagnosis in our case.

The majority of meningiomas are benign tumors associated with favorable outcomes; however, the less common aggressive variants with unfavorable outcomes often recur and may be due to subpopulations of less-differentiated cells residing within the tumor. These subpopulations of tumor cells have tumor-initiating properties and may be isolated from heterogeneous tumors when sorted or cultured in defined medium. We report the isolation and characterization of a population of tumor-initiating cells derived from an atypical meningioma. We identify a tumor-initiating population from an atypical meningioma, termed meningioma-initiating cells (MICs). These MICs self-renew, differentiate, and can recapitulate the histological characteristics of the parental tumor when transplanted at 1000 cells into the flank regions of athymic nude mice. Immunohistochemistry reveals stem-like protein expression patterns similar to neural stem and progenitor cells (NSPCs) while genomic profiling verified the isolation of cancer cells (with defined meningioma chromosomal aberrations) from the bulk tumor. Microarray and pathway analysis identifies biochemical processes and gene networks related to aberrant cell cycle progression, particularly the loss of heterozygosity of tumor suppressor genes CDKN2A (p16(INK4A)), p14(ARF), and CDKN2B (p15(INK4B)). Flow cytometric analysis revealed the expression of CD44 and activated leukocyte adhesion molecule (ALCAM/CD166); these may prove to be markers able to identify this cell type. The isolation and identification of a tumor-initiating cell population capable of forming meningiomas demonstrates a useful model for understanding meningioma development. This meningioma model may be used to study the cell hierarchy of meningioma tumorogenesis and provide increased understanding of malignant progression., (Copyright © 2010 Elsevier Inc. All rights reserved.)

Objective: To investigate clinical characteristics of patients with malignant tumors of Meckel's cave with two illustrative cases. A comparative analysis of clinical features of malignant tumors of Meckel's cave with meningioma and schwannoma of Meckel's cave is discussed., Methods: We report two cases of malignant tumors involving Meckel's cave. We identified 19 additional cases of malignant tumors of Meckel's cave in the literature. We analyzed the symptoms, results of neurological and radiographic examination, pre-operative diagnosis and final diagnosis of these tumors. Our findings were then compared with well described case series of meningioma and schwannoma involving Meckel's cave., Results: Of the 21 patients with malignant tumor involving Meckel's cave, 76% (16/21) had pain, 67% (14/21) had paraesthesia, 89% (17/21) had objective evidence of trigeminal sensory involvement and 42% (8/21) had objective evidence of trigeminal motor involvement. In contrast, of patients with trigeminal schwannomas [1], only 23% presented with pain, 36% with paraesthesia, 74% with objective evidence of trigeminal involvement and 42% with trigeminal motor involvement. Pain and paraesthesia were seen more often in malignant tumors. In Delfini et al.'s [2] series of meningiomas involving Meckel's cave, 81% of patients presented with pain, 25% with paraesthesia, 63% with trigeminal sensory deficits and only 13% with trigeminal motor involvement. Patients with malignant tumors were more likely to be older, and have paraesthesia in comparison with patients with meningioma., Conclusion: Subtle clinical clues may help differentiate malignant from benign involvement of Meckel's cave. We emphasize the need to thoroughly investigate patients early for a possible primary as well as metastases, in those found to have a lesion in the Meckel's cave., (Copyright © 2010 Elsevier B.V. All rights reserved.)