Primary malignant mesenchymoma of bone is a rare neoplasm consisting of two or more unrelated tissue elements other than a fibrosarcomatous component. To our knowledge, only six cases have been reported in the literature. A case of malignant mesenchymoma composed of rhabdomyosarcoma, chondrosarcoma, and osteosarcoma arising within the right acetabulum, resulting in the patient's death 4 months after presentation, is reported, and the literature is reviewed, with a discussion of the similarities to dedifferentiated chondrosarcoma.

The ductular accumulation of "abnormal mucus" is the key histologic feature in cystic fibrosis. This material is periodic acid-Schiff positive and diastase resistant, suggesting that it is glycoprotein in nature. We used the avidin-biotin-peroxidase method to identify this material using antibodies to the serum glycoproteins carcinoembryonic antigen, alpha 1-antitrypsin, and alpha-fetoprotein on paraffin sections of pancreas obtained from a total of 21 patients: 9 with cystic fibrosis, 5 with chronic pancreatitis, and 7 controls. The control patients had normal pancreatic histologic findings, no alpha 1-antitrypsin or alpha-fetoprotein was demonstrated, and only the ductular epithelium reacted weakly for carcinoembryonic antigen. The pancreas in pancreatitis showed fibrosis, acinar atrophy, and ectasia of the ducts that contained only a small amount of periodic acid-Schiff-positive material. This material reacted weakly for carcinoembryonic antigen and alpha 1-antitrypsin. The appearance of the pancreas in cystic fibrosis was similar to that in chronic pancreatitis. However, the ducts contained a greater amount of periodic acid-Schiff-positive material, mostly in the form of globules that reacted strongly for carcinoembryonic antigen and alpha 1-antitrypsin and weakly for alpha-fetoprotein, as did the ductular epithelium. This study shows that the periodic acid-Schiff-positive material in cystic fibrosis contains at least the three serum glycoproteins and that the accumulation may represent a possible defect in cellular synthesis, assembly, or transport of glycoproteins in the ducts.

A case of bile duct adenomas in association with heterozygous (MZ) deficiency of alpha 1-proteinase inhibitor (API) is presented. The salient features were the presence of large API-containing globules in the adenomatous tissue and only minimally, in granular form, in hepatocytes. alpha 1-Proteinase inhibitor was not demonstrated in portal bile ducts entrapped in the adenomatous tissue or in bile ducts present in the liver parenchyma. Bile duct markers such as cytokeratin and carcinoembryonic antigens were present in the adenomatous tissue and also in the normal bile ducts, but not in the hepatocytes, suggesting that the adenomatous structures are ductular in origin, and probably not from ductular metaplasia of liver cells. Accumulation of API is postulated to be a triggering factor in neoplastic transformation.