Calcifying fibrous pseudotumor of pleura. A report of three cases of a newly described entity involving the pleura.

A newly recognized distinctive fibrous soft tissue lesion called "calcifying fibrous pseudotumor" (CFPT) was recently described in the soft tissues of the extremities, trunk, scrotum, groin, neck, or axilla. To date, CFPT has not been described in the pleura. The authors reviewed the clinical, radiologic, and pathologic features of three cases. A 23-year old woman and 34-year old man who presented with chest pain, and a 28-year old woman without chest symptoms were found to have a pleural mass on chest radiographs. Computed tomography (CT) scans of each patient revealed pleural-based nodular masses with central areas of increased attenuation due to calcifications. Each lesions consisted of circumscribed, but unencapsulated masses of hyalinized collagenous fibrotic tissue interspersed with lymphoplasmacytic infiltrates and calcifications, many of which had psammomatous features. The lesions were limited to the pleura and did not involve the underlying lung parenchyma. Electron microscopy in one case showed fibroblasts scattered in dense collagenous tissue. Calcifying fibrous pseudotumor is distinct from other pleural lesions such as fibrous tumor of pleura, calcified granulomas, calcified pleural plaques, and chronic fibrous pleuritis as well as intrapulmonary lesions such as hyalinizing granuloma, inflammatory pseudotumor, and amyloid. As in the soft tissues, local excision appears adequate therapy for CFPT of the pleura. If these lesions behave in a similar fashion to CFPT of soft tissues, one might expect a low frequency of local recurrence.