Primary pulmonary meningioma. Report of a case and review of the literature

Primary pulmonary meningioma (PPM) is a rare disease and usually presents as a solitary pulmonary nodule (SPN). These lesions are mostly benign, but malignant PPMs have been reported, and primary lung cancer or metastasis may be suspected on imaging. We report one case of benign PPM, with a review of 37 cases published in the literature. Diagnostic work-up included radiological chest study and in 3 cases positron emission tomography (PET) showing increased uptake, highly suspicious for malignancy. After exclusion of 13 cases lacking radiological studies of the central nervous system (CNS), 25 patients with radiological data and histological assessment confirming PPM were considered in the analysis. All patients underwent surgical resection except for 1 case with diagnosis at autopsy. Histological assessment revealed benign PPMs in 23 cases (including all 3 cases with positive PET) and malignant PPMs in 2 cases. No recurrence was observed in long-term follow-up of patients with benign PPMs, but the two malignant PPMs relapsed. PPM is an uncommon SPN, so that it can be misdiagnosed and its management unsuited. Indeed, 8 patients (32%) were overtreated with major thoracic surgical resection or with chemotherapy. When feasible, pulmonary wedge resection by video-assisted thoracic surgery (VATS) including intra-operative histological examination is the most suitable approach to determine the diagnosis and the volume of pulmonary resection.