Primary pulmonary meningioma mimicking lung metastatic tumor: a case report.

BACKGROUND: Primary pulmonary meningioma (PPM) is an extremely rare benign tumor. Previous reports indicated that CT features of PPM are single, solid, well-demarcated, homogeneous mass. In this study, we report a case of PPM with atypical CT features.

CASE PRESENTATION: A 65-year-old female presents to clinic with 1-week acute upper respiratory tract infection. Her chest CT scan revealed a 25-29 mm, round-like, heterogeneous lobulated solitary pulmonary nodule in the right lower lobe. Based on the microscopic features and a wide range of immunohistochemical examinations including vimentine, progesterone receptor (PR), CD34 and S100, the mass was diagnosed as PPM after surgery.

CONCLUSION: PPM is a rare disease, CT features of PPM could be heterogeneous and lobulated. Expression of vimentine, PR, CD34 and S100 helps to diagnosis of PPM.