Metastatic Disease:

Clinical:

Neoplastic disease of the pleura is more commonly the result of metastatic dissemination than from primary tumor. Metastatic seeding of the pleura is most commonly seen in lung, breast, ovarian, and gastrointestinal carcinomas [2]. Other tumors with a predilection for pleural spread include thymomas, renal cell carcinomas, and melanoma [2]. Pleural mets often produce exudative pleural effusions. Other findings indicative of malignant pleural disease include the presence of focal, nodular pleural based masses, circumferential pleural thickening, parietal pleural thickening greater than 1 cm, and mediastinal pleural involvement.

Osteosarcoma: Osteosarcoma mets may coat or envelop the pleura. It may mimic the appearance of pleural calcification caused by prior infection or old hemothorax. Extension into the fissures may also occur.

REFERENCES:

(1) AJR 1997; Thoracic involvement from osteosarcoma: typical and atypical CT manifestations.168: 347-349 (no abstract available)

(2) AJR 2012; Makis W, et al. Spectrum of malignant pleural and pericardial disease on FDG PET/CT. 198: 678-685