[Differential diagnosis of pleural diseases].

Diffuse and circular focal processes are radiologically recognized as possibly pleurally conditioned by the position near to the chest wall. A clarification is possible by means of the diagnostic pneumothorax, the pleuroscopy and the exploratory excision under vision. Callous processes may be of inflammatory and malignant genesis. Transthoracic punctures, punch biopsies and surgical exploration may become necessary for the clarification. The effusion is the most frequent symptom of pleural diseases. The differentiation of transudate and exudate is diagnostically as essential as a functional interpretation of the cell sediments of above all inflammatory effusions. Not all malignant processes are cyto-morphologically to be recognized as such. By means of the determination of the protein coagulation after Weltmann, simultaneously performed in the blood serum and in the effusion into the pleura, we, therefore, try to find additional informations. The colorimetric measuring of the contents of hyaluronic acid of pleura exudates serves the identification of diffuse mesotheliomas.