Undifferentiated (embryonal) sarcoma of the liver with alpha-1-antitrypsin deposits: immunohistochemical and ultrastructural studies.

Periodic acid-Schiff-positive diastase-resistant globules are described in an undifferentiated (embryonal) sarcoma of the liver in a 14-year-old boy. These globules were shown to contain alpha-1-antitrypsin (A-1-AT) protein by immunofluorescence techniques. Further immunohistochemical studied revealed albumin and gamma globulins, but no alpha-feto protein (AFP). Electron microscopic studies showed large, electron-dense bodies consistent with phagolysosomal structures, and distinct from that described in alpha-1-antitrypsin deficiency (A-1-ATD). These findings suggested that the globules in this tumor may represent trapping of serum proteins by the malignant cell. These observations are discussed in connection with recent studies linking the deficiency disease and epithelial hepatic tumors.