A malignant seroma in the subscapular region of the chest wall developed postoperatively in a 51-year-old man with a malignant right pleural mesothelioma treated with extrapleural pneumonectomy. Computed tomography revealed the direct communication of the seroma with the hydrothorax. Correlation of CT and pathologic findings is made and the mechanism for the development of such a malignant seroma is proposed. © 1984 Raven Press, Ltd.
