Extent of Hyperostotic Bone Resection in Convexity Meningioma to Achieve Pathologically Free Margins

Abstract

Objective : Hyperostosis in meningiomas can be present in 4.5% to 44% of cases. Radical resection should include aggressive removal of invaded bone. It is not clear however to what extent bone removal should be carried to achieve pathologically free margins, especially that in many cases, there is a T2 hyperintense signal that extends beyond the hyperostotic bone. In this study we try to investigate the perimeter of tumour cells outside the visible nidus of hyperostotic bone and to what extent they are present outside this nidus. This would serve as an initial step for setting guidelines on dealing with hyperostosis in meningioma surgery. Methods : This is a prospective case series that included 14 patients with convexity meningiomas and hyperostosis during the period from March 2017 to August 2018 in two university hospitals. Patients demographics, clinical, imaging characteristics, intraoperative and postoperative data were collected and analysed. In all cases, all visible abnormal bone was excised bearing in mind to also include the hyperintense diploe in magnetic resonance imaging (MRI) T2 weighted images after careful preoperative assessment. To examine bony tumour invasion, five marked bone biopsies were taken from the craniotomy flap for histopathological examinations. These include one from the centre of hyperostotic nidus and the other four from the corners at a 2-cm distance from the margin of the nidus. Results : Our study included five males (35.7%) and nine females (64.3%) with a mean age of 43.75 years (33-55). Tumor site was parietal in seven cases (50%), fronto-parietal in three cases (21.4%), parieto-occipital in two cases (14.2%), frontal region in one case and bicoronal (midline) in one case. Tumour pathology revealed a World Health Organization (WHO) grade I in seven cases (50%), atypical meningioma (WHO II) in five cases (35.7%) and anaplastic meningioma (WHO III) in two cases (14.2%). In all grade I and II meningiomas, bone biopsies harvested from the nidus revealed infiltration with tumour cells while all other bone biopsies from the four corners (2 cm from nidus) were free. In cases of anaplastic meningiomas, all five biopsies were positive for tumour cells. Conclusion : Removal of the gross epicentre of hyperostotic bone with the surrounding 2 cm is adequate to ensure radical excision and free bone margins in grade I and II meningiomas. Hyperintense signal change in MRI T2 weighted images, even beyond visible hypersototic areas, doesn't necessarily represent tumour invasion.

Peculiarities of Atypical Meningiomas: Literature Review

“…As far as AM is concerned, after total resection, the rate of recurrence is of ∼ 40%, and survival is of ∼ 11.8 years. 11 19 Of the prognosis markers, K i -67 is related to the rate of survival, and patients who present K i -67 < 10% have a 60% higher rate of survival when compared with patients with K i -67 > 10%. 33 Another factor related to the increase in AM patient survival is being under 60 years of age, and undergoing Simpson grade I resection ( p = 0.055).…”

“…Meningiomas are responsible for more than 30% of CNS tumors, with an incidence between 4.4 and 6 per 100 thousand inhabitants, and AMs consitute 4.2% to 15% of the cases. [9][10][11] In general, meningiomas are more common in women aged between 50 and 60 years; however, WHO grade-II meningiomas are more prevalent in older males, usually between 60 and 70 years of age. 8,9,12 This epidemiological difference seems to be explained by the influence of estrogen in the pathogenicity of WHO grade-I meningiomas, which does not occur with grade-II or grade-III meningiomas.…”

Cranioplasty With Customized Craniofacial Implants and Intraoperative Resizing for Single-Stage Reconstruction Following Oncologic Resection of Skull Neoplasms

“…As such the field of craniofacial surgery, which is primarily focused on pediatric patients is limited when applied to this complex subset of patients. 24,25 In our experience, the single stage cranioplasty approach following skull tumor resection is a safe and practicable approach in the properly selected patient and requires only a small aspect of an artistic eye which is consisted with neuroplastic surgery. Primary skull tumors, intraosseous and hyperostotic meningiomas and metastatic disease involving the calvarium lend themselves particularly well to this approach.…”

“…As such the field of craniofacial surgery, which is primarily focused on pediatric patients is limited when applied to this complex subset of patients. 24,25…”

Angiosarcoma on Top of a Meningioma Mimicking a Transosseous Meningioma: an Interdisciplinary Point of View

“…Hyperostosis can be found in 4.5 to 44%. 6 In atypical meningiomas, bone involvement is a predictor for poor outcome. 7 Bone infiltration can be identified with high specificity and sensitivity preoperatively via 68 Ga-DOTATATE positron emission tomography (PET)/ computed tomography (CT) 8 and via 5-aminolevulinic acid (5-ALA) fluorescence during surgery, which can improve the extent of tumor resection.…”