Meningiomas - consequences of incidental detection and novel classification

Abstract

Aim Meningiomas are often benign, slow-growing tumors found in older individuals. This thesis aimed to examine the occurrence of incidental meningioma, the surgical and quality of life outcomes after surgery and to evaluate the use of newer classification methods in the diagnosis and prognostication of meningiomas.

Methods Papers I and IV utilize a retrospective, matched case-control design to explore the surgical and quality of life outcomes after surgery for incidental meningiomas. Paper II replicates and validates a new classification scheme for meningioma using immuno-histochemical markers. Paper III studies the incidence and management of incidental meningiomas between 2008-2009 and 2018-2019.

Results Paper I found that asymptomatic patients have significantly more complications after surgical resection than symptomatic patients. Paper II found that the proposed immunohistochemical markers lacked clinical applicability and could not more accurately predict progression-free or overall survival. Paper III found no difference in the incidence of incidental meningiomas over time, but patients have become older and have other malignancies. No patient died due to their meningioma. In paper IV, no differences in health-related quality of life were seen between patients and the general public. A third of patients did not return to their preoperative occupation.

Conclusion The incidence of incidental meningioma has not increased in the last decade, but patients are older, more often have a diagnosis of cancer, and it is uncommon that individuals die from their meningioma. When surgically removed, the complication rate is higher for asymptomatic than symptomatic meningiomas. The validated classification model needs further refinement before it can be taken into clinical use and does not contribute more accurate prognostication than the WHO classification. At long-term follow up, patients with surgically removed asymptomatic meningioma do not report worse health-related quality of life than the general public, but a large proportion of patients never return to work post-operatively.