2026 Poster Presentations
P153: PREGNANCY-ASSOCIATED ACCELERATION OF MENINGIOMAS: A CASE SERIES OF THREE PATIENTS
Maxwell A Marino1; Ali O Jamshidi, MD2; 1Riverside University Health System; 2Kaiser Permanente Woodland Hills Medical Center
Introduction: Meningiomas are generally indolent, but their growth can be influenced by hormonal, vascular, and metabolic changes. Pregnancy presents a unique milieu of elevated progesterone, increased blood volume, and tissue edema, which may accelerate tumor progression and worsen mass effect. Although pregnancy-associated meningioma growth is rare, it presents significant diagnostic and management challenges due to risks for both mother and fetus. We present three illustrative cases demonstrating symptomatic meningioma progression during pregnancy, emphasizing clinical presentation, radiographic evolution, operative management, and pathology.
Methods: A retrospective review was performed of three women with meningiomas whose growth was temporally associated with pregnancy. Clinical presentation, imaging, operative details, histopathology, and outcomes were extracted from the medical record and analyzed.
Results: Case 1: A 40-year-old multiparous woman presented postpartum with mild visual blurring. Imaging revealed an enlarging right paraclinoid mass that had demonstrated interval growth following pregnancy. She underwent right frontotemporal craniotomy with anterior clinoidectomy. Pathology showed meningothelial meningioma, WHO grade I, with progesterone receptor positivity and PIK3CA mutation. She recovered without deficit and remains radiographically disease-free.
Case 2: A 33-year-old gravida 2 presented at 37 weeks gestation with progressive left hemifacial numbness, frequent epistaxis, and a palpable facial mass. MRI revealed a 4 × 3 × 4 cm left spheno-cavernous meningioma extending through the skull base with ICA encasement. Subtotal resection was achieved via pterional craniotomy; pathology confirmed WHO grade I mixed fibrous/meningothelial meningioma with low proliferative index (Ki-67 <1%). Residual tumor remained stable on follow-up. Pregnancy proceeded to term without obstetric complications.
Case 3: A 41-year-old gravida 3 with prior meningioma resection presented in early pregnancy. MRI demonstrated recurrent right spheno-cavernous meningioma with optic nerve and ICA encasement. She underwent repeat craniotomy with subtotal resection, leaving residual disease in the cavernous sinus. Pathology showed WHO grade I meningothelial meningioma with PR positivity and low Ki-67 (<4%); molecular testing again revealed PIK3CA mutation. She recovered without neurological deficit and continues high-risk obstetric surveillance.
Across all three cases, pregnancy appeared temporally associated with radiographic tumor growth or symptomatic progression. Pathology demonstrated benign WHO grade I histology with hormonal receptor positivity in two cases, and molecular analysis revealed PIK3CA mutations in two patients. Maternal outcomes were favorable, and no fetal complications were reported.
Conclusion: Pregnancy-associated acceleration of meningiomas is rare but clinically significant, with implications for both maternal neurological status and fetal safety. Multidisciplinary coordination between neurosurgery, neuro-oncology, and obstetrics is essential in management. While histology is typically benign, hormonal receptor expression and specific molecular alterations may contribute to pregnancy-associated growth. These cases highlight the need for close radiographic surveillance of known meningiomas in women of reproductive age and underscore the importance of individualized surgical decision-making regarding timing of intervention relative to pregnancy.
