Primary pulmonary meningioma: A case report and review of the literature

Abstract

Background: Primary pulmonary meningioma (PPM) is a rare disease that is usually benign. The most common presentation of PPM is isolated pulmonary nodules or masses, so the disease can mimic any other lung tumor on imaging, especially lung cancer or metastasis.

Case summary: A 47-year-old asymptomatic woman presented with a well-defined, lobulated pulmonary mass with calcification in the left lower lobe. The mass measured 69 mm × 57 mm × 61 mm and was found during a chest computed tomography (CT) performed for physical examination. Contrast-enhanced CT and positron emission tomography (PET)/CT revealed mild enhancement of the mass, with accumulation of 18-fluoro-2-deoxy-D-glucose (¹⁸F-FDG). Transbronchial biopsy suggested a provisional diagnosis of low-grade neuroendocrine tumor. Subsequent enhanced head magnetic resonance imaging revealed no positive lesions. An open cuff resection of the left lower lobe and wedge resection of the lingual segment were performed. Histopathological and immunohistochemical examination revealed that the mass was a PPM.

Conclusion: PPM should be considered in the differential diagnosis of isolated pulmonary masses found incidentally on CT and should be diagnosed based on a combination of radiological and histological features. Surgical resection is currently the main treatment strategy. No recurrence of benign PPMs has been reported after complete resection.

Keywords: Case report; Contrast-enhanced computed tomography; Positron emission tomography; Primary pulmonary meningioma.

Figure 1

Contrast-enhanced chest computed tomography images of (A, B) unenhanced and (C) enhanced scan. A 6.9-cm diameter well-circumscribed mass in the left lower lobe of the lung shows mild homogeneous enhancement.

Figure 2

Positive uptake by the mass on ¹⁸F-fluorodeoxyglucose-positron emission tomography suggesting malignancy.

Figure 3

The transbronchial biopsy result: Hematoxylin and eosin staining showed that a few nested epithelioid cells and abnormal cells were observed in the tissue (200×).

Figure 4

Histological features of primary pulmonary meningioma. A-D: Macroscopically, primary pulmonary meningioma (PPM) showed as spindle or oval cells organized in bundles and whorls on hematoxylin-eosin staining (25×; 50×; 100×; 200×); E-H: Immunohistochemically (200×), PPM showed negativity for E: Cytokeratin, positive for F: Epithelial membrane antigen; G: Progesterone receptor; H: Somatostatin Receptor 2 (SSTR2).