A case of pulmonary alveolar proteinosis with high levels of tumor markers

Abstract

We report a case of pulmonary alveolar proteinosis (PAP) in which the serum levels of CEA, CA15-3, and TPA, as well as the whole lung lavage fluid levels of CEA, CA19-9, CA125, CA15-3, CA50, SLX, SCC, and TPA were high. The patient was a 39-year-old man who presented with exertional dyspnea, and nonsegmental bilateral reticular infiltration shadows in the middle and lower lung fields on the chest radiograph. A diagnosis of proteinosis was confirmed by histopathology of the transbronchial lung biopsy (TBLB) specimen, biochemical analysis of the phospholipids, and an electron microscopic study of lavage fluid. Whole lung lavages alleviated his symptoms, effaced the shadows on the chest radiographs and brought the blood gas values closer to normal. An immunohistochemical study of TBLB specimens showed that CEA, CA153, and SLX were positively stained in the alveolar epithelia. With repeated lavage, tumor markers (CEA, CA15-3, TPA) in the fluid decreased. These results suggest that the alveolar epithelia indeed produced these tumor marker molecules. In PAP, it is well recognized that CEA may be high in at least one of the following: serum, bronchoalveolar lavage fluid, and whole lung lavage fluid. To date, however, the site of production of such tumor markers had not been clearly demonstrated to be in the lung tissue. This case is interesting because there are few reports of PAP with high levels of tumor markers in the serum and whole lung lavage fluid, and because the tumor markers found in abnormally high amounts in this patient were produced by alveolar epithelia.