Meningioma and Other Meningeal Tumors.

Meningiomas develop from meningothelial cells and approximately account for more than 30 percent of central nervous system (CNS) tumors. They can occur anywhere in the dura, most often intracranially and at dural reflection sites. Half of the cases are usually at parasagittal/falcine and convexity locations; other common sites are sphenoid ridge, suprasellar, posterior fossa, and olfactory groove. The female-to-male ratio is approximately 2 or 3-1, and the median age at diagnosis is 65 years. Meningiomas are generally extremely slow-growing tumors; many are asymptomatic or paucisymptomatic at diagnosis and are discovered incidentally. Clinical manifestations, when present, are influenced by the tumor site and by the time course over which it develops. Meningiomas are divided into three grades. Grade I represents the vast majority of cases; they are considered typical or benign, although their CNS location can still lead to severe morbidity or mortality, resulting in a reported ten-year net survival of over 80%. Atypical (WHO grade II) meningiomas are considered "intermediate grade" malignancies and represent 5-7% of cases. They show a tendency for recurrence and malignant degeneration with a relevant increase in tumor cell migration and surrounding tissue infiltration; ten-year net survival is reported over 60%. The anaplastic subtype (WHO III) represents only 1-3% of cases, and it is characterized by a poor prognosis (ten-year net survival of 15%). The treatment of choice for these tumors stands on complete microsurgical resection in case the subsequent morbidities are assumed minimal. On the other hand, and in case the tumor is located in critical regions such as the skull base, or the patient may have accompanied comorbidities, or it is aimed to avoid intensive treatment, some other approaches, including stereotactic radiosurgery and radiotherapy, were recommended as safe and effective choices to be considered as a primary treatment option or complementary to surgery. Adjuvant radiosurgery/radiotherapy should be considered in the case of atypical and anaplastic histology, especially when a residual tumor is identifiable in postoperative imaging. A "watchful waiting" strategy appears reasonable for extremely old individuals and those with substantial comorbidities or low-performance status, while there is a reduced threshold for therapeutic intervention for relatively healthy younger individuals due to the expectation that tumor progression will inevitably necessitate proactive treatment. To treat and manage meningioma efficiently, the assessments of both neurosurgeons and radiation oncologists are essential. The possibility of other rarer tumors, including hemangiopericytomas, solitary fibrous tumors, lymphomas, metastases, melanocytic tumors, and fibrous histiocytoma, must be considered when a meningeal lesion is diagnosed, especially because the ideal diagnostic and therapeutic approaches might differ significantly in every tumor type.

Meningioma in a Postrenal Transplant Case: More than Meets the Eye.

BACKGROUND: Patients with a renal transplant are an ever-increasing demographic. Their life expectancy is also on the rise and thus malignancies or tumors in these cases are more frequent. These patients are often on immunosuppressive drugs that are known to cause changes in the microvasculature, especially of the deep white matter. However, benign dural-based lesions are a rarity in these cases with very few (<5) ever being reported. Imaging findings in such cases are altered, which leads to an altered set of differential diagnosis. CASE DESCRIPTION: We present a case of a right parasagittal lesion in case of postrenal transplant with imaging findings suggestive of an inflammatory lesion. The lesion was excised and histopathology was that of a fibrous meningioma. Pathological basis of altered imaging is discussed and potential causes elaborated along with a thorough review of similar cases and their findings. CONCLUSIONS: Renal transplants and long-term survival are now a reality; calcineurin inhibitors are a staple for these cases. The drugs alter imaging findings and hence cases need to be carefully evaluated with a host of differential diagnosis. Knowledge of these changes is now necessary for these new spectra of cases.

Supratentorial dural-based collision of cavernoma and meningioma: a case report.

BACKGROUND: Collision tumor is a very rare case of cerebral lesion. Approximately 50 reports of intracranial collision tumors were described in the literature. We present a case of supratentorial dural-based convexity collision tumor radiologically mimicking cavernous malformation and composed of cavernous malformation and meningioma. CASE PRESENTATION: The case presents a 63-year-old female having MR findings such as hemorraged supratentorial dural-based mass with "popcorn" signs and hemosiderin deposits. The patient underwent craniotomy and evacuation of the subdural hematoma with resection of the tumor mass. Histologically the lesion had signs of a cavernoma and meningioma. MRI in a year after surgery did not reveale residual tumor mass or recurrence. CONCLUSIONS: Collision tumor is a very rare case. Preoperative diagnosis of a dural lesion is difficult and challenging. A neuroradiological differential diagnosis of similar cases needs focused attention.