Meningoids: Lesions mimicking meningiomas

Introduction: Dural based lesions, often misinterpreted as meningiomas, may have deleterious impact on patient care and may mislead the presurgical treatment algorithm. The study proposes the term 'Meningoids' for clubbing intracranial lesions which clinically and radiologically mimic meningiomas. The study also defines the various features of such lesions which help to raise a suspicion in surgeon's mind and also prepares him for possible intra and post-operative challenges and surprises. Materials and methods: All patients presenting with a preoperative radiological diagnosis of meningioma and a final histopathological diagnosis other than meningioma were included in the study. Patients were recognised and their relevant radiological profiles were retrospectively drawn and assessed in terms of variables based on plain and contrast enhanced CT scan and MRI findings. Data was presented in a tabulated form and variables were analysed based on features mimicking and atypical of meningioma. Results: A total of 9 patients were included in the study. A final diagnosis of tuberculoma and hemangioblastoma were made in 2 patients each. One patient each had a final diagnosis of sarcoidosis, non hodgkin's lymphoma, chondroma, ependymoma and metastasis from adenocarcinoma. On retrospectively analysing the data, the following findings were found to raise a high index of suspicion for a meningoid: cystic changes, disproportionate oedema, erosive bony changes, atypical dural tail, flow voids around the lesion and intraoperative gross features. Conclusion: Its not uncommon for neurosurgeons to encounter dural based lesions mimicking meningioma and being prepared preoperatively with 'meningoids' would be important to optimise outcomes, minimise morbidity and most importantly forcing the neurosurgeon to think critically which is eventually helpful in prognostication.