What is a meningioma in a 30-year-old female patient?

What is a Meningioma?

A meningioma is a tumor that arises from arachnoid cells (meningothelial cells) in the meninges—the protective membranes surrounding the brain and spinal cord—and represents approximately one-third of all primary central nervous system tumors. 1, 2

Origin and Cellular Characteristics

• Meningiomas develop from meningothelial cells within the leptomeninges, specifically from arachnoid cap cells 3
• These tumors can occur anywhere meninges or ectopic meninges exist, including unusual anatomical sites such as the nasal cavity, paranasal sinuses, middle ear, and even the mediastinum 1
• Classic histologic features include whorl formations, psammoma bodies, nuclear holes, and nuclear pseudoinclusions 3

Common Locations

• Up to 90% of meningiomas are supratentorial or intraventricular in location 1
• The most common location is the convexity of the cerebral hemispheres 1
• Other frequent sites include parasagittal/falcine regions, sphenoid ridge, suprasellar area, posterior fossa, and olfactory groove 2
• Meningiomas can also develop in the spinal canal, optic nerve sheath, and occasionally completely intraparenchymal without obvious dural attachment 1

Age and Sex Distribution Relevant to a 30-Year-Old Female

• In adults, meningiomas show a female predominance with a female-to-male ratio of approximately 2-3:1 2
• The median age at diagnosis is typically 65 years, making a 30-year-old patient younger than the typical presentation age 2
• However, there is a second peak in age distribution during the second decade of life, and patients presenting in their 20s-30s have a clinical course that mirrors adults 1
• A 30-year-old female falls into the age range where genetic syndromes should be considered, as 20-40% of younger patients with meningiomas have Neurofibromatosis type 2 (NF-2), even without other clinical manifestations 1

Clinical Behavior and Growth Pattern

• Meningiomas are generally extremely slow-growing tumors 2
• Many are asymptomatic or minimally symptomatic at diagnosis and are discovered incidentally 2
• When symptoms are present, they depend on tumor location and include headaches, focal neurological deficits, cranial nerve palsies, and seizures (in up to 30% of cases) 1, 4
• Symptoms of raised intracranial pressure such as drowsiness and vomiting are common presenting features 1

Tumor Grading and Prognosis

• WHO Grade I (benign/typical) meningiomas represent approximately 90% of cases, with a 10-year net survival exceeding 80% 2, 5
• WHO Grade II (atypical) meningiomas represent 5-7% of cases, show tendency for recurrence, and have a 10-year net survival over 60% 2
• WHO Grade III (anaplastic) meningiomas represent only 1-3% of cases with a 10-year net survival of 15% 2

Genetic and Molecular Features

• The initial cytogenetic event is thought to involve loss of genetic material on the long arm of chromosome 22 (22q12), near the NF-2 gene 1
• Progesterone receptors are expressed in meningiomas, which is not age-dependent 1
• In younger patients, specific chromosomal abnormalities including 1p and 14q deletions are associated with higher risk of tumor recurrence 1

Risk Factors to Consider in a 30-Year-Old

• History of high-dose cranial irradiation during childhood for other malignancies increases risk 1, 4
• Family history of NF-2, Gorlin syndrome, or Rubinstein-Taybi syndrome should be assessed 1
• Rare familial meningiomas without underlying genetic syndrome have been described 1