A Case of Primary Pulmonary Meningioma With Genetic Characterization and Literature Review.

Abstract

Primary pulmonary meningiomas (PPMs) are exceptionally rare tumors, accounting for a small fraction of ectopic meningiomas found outside the central nervous system (CNS). These tumors are typically benign, with only 5%-8% being malignant. Since the first reported case in 1982, fewer than 100 cases have been documented. We report a unique case of PPM in a 58-year-old male detected incidentally during lung cancer screening. Histopathological and immunohistochemical (IHC) analysis confirmed the diagnosis, and next-generation sequencing (NGS) revealed a Neurofibromatosis Type 2 (NF2) inactivating mutation and a likely subclonal PALB2 mutation-findings not commonly reported in the PPM literature. Our comprehensive review of 70 reported cases reveals a female predominance, asymptomatic presentation in most cases, and strong IHC positivity for EMA, PR, and vimentin. Malignant cases tended to be larger and more symptomatic. Our case highlights the value of molecular profiling in differentiating PPMs from other pulmonary neoplasms and CNS metastases. Given the emerging role of NGS in identifying tumor-specific mutations, further exploration of the genetic landscape of PPMs is warranted. Recognition of NF2 mutations as potential drivers may open new avenues for targeted therapies and long-term monitoring strategies in affected individuals.