Primary intrapulmonary meningiomas: A clinicopathologic and immunohistochemical study of ten cases

BACKGROUND. Primary intrapulmonary meningiomas are rare, and their occurrence has been reported in the literature only sporadically. METHODS. The clinical, pathologic, and immunohistochemical features of ten cases of primary intrapulmonary meningioma were reviewed. RESULTS. The patients were 4 women and 6 men between the ages of 30 and 72 years (mean age: 51 years). In nine patients, the lung tumor was found during a routine chest radiographic study. The only patient with clinical symptomatology was a man who presented with a persistent cough of 45 days' duration. None of the patients had a previous history of central nervous system (CNS) meningioma or other tumor at the time of diagnosis. Macroscopically, the neoplasms were described as soft, white, well circumscribed lesions that ranged in size from 1.5 cm to 4 cm in greatest dimension. No predilection for any particular lobe or segment of lung was observed. Histologically, all the tumors showed the characteristic growth pattern of CNS meningiomas and were classified accordingly. Seven tumors were transitional meningiomas, and three were fibrous meningiomas Psammoma bodies were observed in 50% of the tumors. Immunohistochemically, six cases showed positive staining for Epithelial Membrane Antigen (EMA) and vimentin, whereas two of these cases also showed focal positive staining for CD34. Clinical follow-up ranging from 1 month to 24 years was obtained for 6 patients. All the patients were alive and well except for 1 female who died 20 years after the initial diagnosis at age 92 of a cerebrovascular accident. CONCLUSIONS. The clinical follow-up in this study suggests that these tumors are amenable to surgical resection, and when the tumor is resected in its entirely, the patient is cured. In addition, the immunohistochemical results suggest that, as in CNS meningiomas, EMA and vimentin are the most reliable immunologic markers for these tumors.