Clinical, Radiologic, and Pathologic Features of 56 Cases of Intracranial Lymphoplasmacyte-Rich Meningioma.

OBJECTIVE: Intracranial lymphoplasmacyte-rich meningioma (LPRM) is rarely reported because of its extremely low incidence, and current understanding of this disease is poor. We analyzed the incidence and clinical, radiologic, pathologic, and prognostic features of intracranial LPRMs.

METHODS: Approximately 10,908 intracranial meningiomas were surgically resected in Beijing Tiantan Hospital between June 2009 and November 2016. All pathologically proven LPRM cases were identified. Statistical analysis was performed to determine which parameters were associated with prognoses and tumor resection.

RESULTS: LPRMs accounted for approximately 0.51% of intracranial meningiomas (56 of 10,908). Patients with LPRM had a mean age of 44.6 years and there was no significant gender preference (28 male and 28 female). Gross total resection was achieved in 45 cases, subtotal resection in 9 cases, and partial resection in 2 cases. At discharge, Karnofsky Performance Scale scores and neurologic function improved in 42 cases (75.0%) and worsened in 14 cases (25.0%). At the 41.5 months median follow-up (range, 5-97 months), 5 patients had tumor recurrence, and the 3-year and 5-year progression-free survival rates were 94.6% and 92.9%, respectively. One patient died of tumor recurrence. At the latest follow-up, Karnofsky Performance Scale scores improved in 48 cases (85.7%), worsened in 7 cases (12.5%), and 1 patient died (1.8%). Univariate analysis showed that the extent of tumor resection and tumors located in the skull base were significantly associated with short-term outcomes. Skull base location was significantly associated with increased risk of worse long-term outcomes. Tumor size ≥45 mm, poorly defined tumor border, and skull base location significantly limited the extent of tumor resection.

CONCLUSIONS: Intracranial LPRM is a rare subtype of meningioma with no gender difference and low recurrence. Long-term survival is expected, although tumors located in the skull base and bone destruction are independent risk factors of poor long-term outcomes. Microsurgical treatment of skull base LPRM remains a formidable challenge because of poorly defined borders and critical neurovascular structure encasement. Radical tumor resection, which induces severe neurologic deficits, is unnecessary.